Removed the parameter use in database drivers' _close() and added a default _close() method in CI_DB_driver + some changelog fixes
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index a955f45..a0812d4 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -1152,7 +1152,7 @@
 	{
 		if ($this->conn_id)
 		{
-			$this->_close($this->conn_id);
+			$this->_close();
 			$this->conn_id = FALSE;
 		}
 	}
@@ -1160,6 +1160,20 @@
 	// --------------------------------------------------------------------
 
 	/**
+	 * Close DB Connection
+	 *
+	 * This method would be overriden by most of the drivers.
+	 *
+	 * @return	void
+	 */
+	protected function _close()
+	{
+		$this->conn_id = FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Display an error message
 	 *
 	 * @param	string	the error message
@@ -1401,7 +1415,7 @@
 	 */
 	public function __destruct()
 	{
-		if ($this->conn_id && ! $this->pconnect)
+		if ( ! $this->pconnect)
 		{
 			$this->close();
 		}
@@ -1410,4 +1424,4 @@
 }
 
 /* End of file DB_driver.php */
-/* Location: ./system/database/DB_driver.php */
+/* Location: ./system/database/DB_driver.php */
\ No newline at end of file
diff --git a/system/database/DB_result.php b/system/database/DB_result.php
index 25b4fb9..690734b 100644
--- a/system/database/DB_result.php
+++ b/system/database/DB_result.php
@@ -378,11 +378,10 @@
 	public function unbuffered_row($type = 'object')
 	{
 		return ($type !== 'array') ? $this->_fetch_object() : $this->_fetch_assoc();
-		
 	}
 
 	// --------------------------------------------------------------------
-	
+
 	/**
 	 * The following functions are normally overloaded by the identically named
 	 * methods in the platform-specific driver -- except when query caching
diff --git a/system/database/drivers/cubrid/cubrid_driver.php b/system/database/drivers/cubrid/cubrid_driver.php
index 1373faa..944df99 100644
--- a/system/database/drivers/cubrid/cubrid_driver.php
+++ b/system/database/drivers/cubrid/cubrid_driver.php
@@ -485,7 +485,7 @@
 	}
 
 	// --------------------------------------------------------------------
-	
+
 	/**
 	 * Limit string
 	 *
@@ -506,15 +506,14 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @param	resource
 	 * @return	void
 	 */
-	protected function _close($conn_id)
+	protected function _close()
 	{
-		@cubrid_close($conn_id);
+		@cubrid_close($this->conn_id);
 	}
 
 }
 
 /* End of file cubrid_driver.php */
-/* Location: ./system/database/drivers/cubrid/cubrid_driver.php */
+/* Location: ./system/database/drivers/cubrid/cubrid_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/interbase/interbase_driver.php b/system/database/drivers/interbase/interbase_driver.php
index 1b18de8..c457f63 100644
--- a/system/database/drivers/interbase/interbase_driver.php
+++ b/system/database/drivers/interbase/interbase_driver.php
@@ -472,12 +472,11 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @param	resource
 	 * @return	void
 	 */
-	protected function _close($conn_id)
+	protected function _close()
 	{
-		@ibase_close($conn_id);
+		@ibase_close($this->conn_id);
 	}
 
 }
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index f60ec81..914de49 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -523,15 +523,14 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @param	resource
 	 * @return	void
 	 */
-	protected function _close($conn_id)
+	protected function _close()
 	{
-		@mssql_close($conn_id);
+		@mssql_close($this->conn_id);
 	}
 
 }
 
 /* End of file mssql_driver.php */
-/* Location: ./system/database/drivers/mssql/mssql_driver.php */
+/* Location: ./system/database/drivers/mssql/mssql_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index 32c5186..161f995 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -520,15 +520,14 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @param	resource
 	 * @return	void
 	 */
-	protected function _close($conn_id)
+	protected function _close()
 	{
-		@mysql_close($conn_id);
+		@mysql_close($this->conn_id);
 	}
 
 }
 
 /* End of file mysql_driver.php */
-/* Location: ./system/database/drivers/mysql/mysql_driver.php */
+/* Location: ./system/database/drivers/mysql/mysql_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index e2684e4..9261883 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -523,16 +523,14 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @param	object
 	 * @return	void
 	 */
-	protected function _close($conn_id)
+	protected function _close()
 	{
 		$this->conn_id->close();
-		$this->conn_id = FALSE;
 	}
 
 }
 
 /* End of file mysqli_driver.php */
-/* Location: ./system/database/drivers/mysqli/mysqli_driver.php */
+/* Location: ./system/database/drivers/mysqli/mysqli_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index 33a89df..e2fa513 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -671,15 +671,14 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @param	resource
 	 * @return	void
 	 */
-	protected function _close($conn_id)
+	protected function _close()
 	{
-		@oci_close($conn_id);
+		@oci_close($this->conn_id);
 	}
 
 }
 
 /* End of file oci8_driver.php */
-/* Location: ./system/database/drivers/oci8/oci8_driver.php */
+/* Location: ./system/database/drivers/oci8/oci8_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/odbc/odbc_driver.php b/system/database/drivers/odbc/odbc_driver.php
index e36f2d2..e317211 100644
--- a/system/database/drivers/odbc/odbc_driver.php
+++ b/system/database/drivers/odbc/odbc_driver.php
@@ -402,15 +402,14 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @param	resource
 	 * @return	void
 	 */
-	protected function _close($conn_id)
+	protected function _close()
 	{
-		@odbc_close($conn_id);
+		@odbc_close($this->conn_id);
 	}
 
 }
 
 /* End of file odbc_driver.php */
-/* Location: ./system/database/drivers/odbc/odbc_driver.php */
+/* Location: ./system/database/drivers/odbc/odbc_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index 89e6967..e38c114 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -667,20 +667,7 @@
 		}
 	}
 
-	// --------------------------------------------------------------------
-
-	/**
-	 * Close DB Connection
-	 *
-	 * @param	object
-	 * @return	void
-	 */
-	protected function _close($conn_id)
-	{
-		$this->conn_id = NULL;
-	}
-
 }
 
 /* End of file pdo_driver.php */
-/* Location: ./system/database/drivers/pdo/pdo_driver.php */
+/* Location: ./system/database/drivers/pdo/pdo_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index 17bd37b..0ddfd0a 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -653,12 +653,11 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @param	resource
 	 * @return	void
 	 */
-	protected function _close($conn_id)
+	protected function _close()
 	{
-		@pg_close($conn_id);
+		@pg_close($this->conn_id);
 	}
 
 }
diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
index 551704f..d710b94 100644
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ b/system/database/drivers/sqlite/sqlite_driver.php
@@ -450,15 +450,14 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @param	resource
 	 * @return	void
 	 */
-	protected function _close($conn_id)
+	protected function _close()
 	{
-		@sqlite_close($conn_id);
+		@sqlite_close($this->conn_id);
 	}
 
 }
 
 /* End of file sqlite_driver.php */
-/* Location: ./system/database/drivers/sqlite/sqlite_driver.php */
+/* Location: ./system/database/drivers/sqlite/sqlite_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/sqlite3/sqlite3_driver.php b/system/database/drivers/sqlite3/sqlite3_driver.php
index d22f6a4..ad2848e 100644
--- a/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -417,10 +417,9 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @param	object (ignored)
 	 * @return	void
 	 */
-	protected function _close($conn_id)
+	protected function _close()
 	{
 		$this->conn_id->close();
 	}
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index 8cc500f..3e9fa7b 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -510,15 +510,14 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @param	resource
 	 * @return	void
 	 */
-	protected function _close($conn_id)
+	protected function _close()
 	{
-		@sqlsrv_close($conn_id);
+		@sqlsrv_close($this->conn_id);
 	}
 
 }
 
 /* End of file sqlsrv_driver.php */
-/* Location: ./system/database/drivers/sqlsrv/sqlsrv_driver.php */
+/* Location: ./system/database/drivers/sqlsrv/sqlsrv_driver.php */
\ No newline at end of file