Add db_set_charset() support for PostgreSQL and change its implementation for 'mysql'
diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index 7108a6d..84f7791 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -147,7 +147,7 @@
 	 * @param	string
 	 * @return	bool
 	 */
-	public function db_set_charset($charset, $collation)
+	protected function _db_set_charset($charset, $collation)
 	{
 		return function_exists('mysql_set_charset')
 			? @mysql_set_charset($charset, $this->conn_id)
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index d668108..8df90f6 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -147,6 +147,19 @@
 	// --------------------------------------------------------------------
 
 	/**
+	 * Set client character set
+	 *
+	 * @param       string
+	 * @return      bool
+	 */
+	protected function _db_set_charset($charset)
+	{
+		return (pg_set_client_encoding($this->conn_id, $charset) === 0);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Database version number
 	 *
 	 * @return	string