Add dummy method reconnect() method to CI_DB_driver and remove it from drivers that don't support it
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index 42b1b35..9f1a0b8 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -171,6 +171,23 @@
 	// --------------------------------------------------------------------
 
 	/**
+	 * Reconnect
+	 *
+	 * Keep / reestablish the db connection if no queries have been
+	 * sent for a length of time exceeding the server's idle timeout.
+	 *
+	 * This is just a dummy method to allow drivers without such
+	 * functionality to not declare it, while others will override it.
+	 *
+	 * @return      void
+	 */
+	public function reconnect()
+	{
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Set client character set
 	 *
 	 * @param	string