[1.2.X] Fixed #12343 -- Added support for connection-by-socket to MySQL using...

[1.2.X] 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.

Backport of r13660 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@13663 bcc190cf-cafb-0310-a4f2-bffc1f526a37