DB charset option

[dik_]

It would be nice to have an option in application/config/database.php like:

$db['default']['charset'] = "utf8";

Then this would call an appropriate query, probably in database/DB.php towards the end (or some other more appropriate place):

$DB =& new $driver($params);
$DB->query("SET NAMES 'utf8'");
return $DB;

replacing utf8 with whatever was set. This way we won't have to change the CI core and forget to do so in an update, and we won't have to call SET NAMES in every constructor (or method).

Thanks

[Shadowhand]

Further fixes in r196.

[Shadowhand]

sqlite, mssql, and oci8 need to be implemented/tested.

[Shadowhand]

Using PDO removes the db-specific drivers that kept this bug open.