[1.1.X] Fixed #13464 -- Reworked module_has_submodule to break the requirement...

[1.1.X] Fixed #13464 -- Reworked module_has_submodule to break the requirement for loader and finder to be the same class. Thanks to Alex Gaynor for the report and patch, and Brett Cannon for suggesting the approach.

Backport of r13082 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.1.X@13085 bcc190cf-cafb-0310-a4f2-bffc1f526a37