Fixed #2791 -- Added __contains__ method (for "a in dict" checks) to MergeDict. Thanks, Ned Batchelder.
Fixed #2791 -- Added __contains__ method (for "a in dict" checks) to MergeDict.
Thanks, Ned Batchelder.

--HG--
extra : convert_revision : svn%3Abcc190cf-cafb-0310-a4f2-bffc1f526a37/django/trunk%403808

adieu/django-nonrel,adieu/django-nonrel,adieu/django-nonrel