Fixed #10762, #17514 -- Prevented the GZip middleware from returning a...

Fixed #10762, #17514 -- Prevented the GZip middleware from returning a response longer than the original content, allowed compression of non-200 responses, and added tests (there were none). Thanks cannona for the initial patch.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@17365 bcc190cf-cafb-0310-a4f2-bffc1f526a37