Fixed #12343 -- Added support for connection-by-socket to MySQL using the...

Fixed #12343 -- Added support for connection-by-socket to MySQL using the dbshell management command. Thanks to elyon001@gmail.com for the report, and sfllaw for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13660 bcc190cf-cafb-0310-a4f2-bffc1f526a37