[Patch] for DB to support table and column quoting

Attached is a patch which adds the quoteEntity() function. This function is meant to provide quoting for table and column names, primarily to allow use of reversed words for table and column names. quoteEntity() should be overridden per driver as needed, just as quote() is. I have included functions for mysql.php and oci8.php. I have also added a small fix for the oci8 connect function to allow for connections without a TNS name set. -- paperCrane <Justin Patrin>