In `MergeDict` class, changed variable names to not clash with `dict` builtin.
In `MergeDict` class, changed variable names to not clash with `dict` builtin.

--HG--
extra : convert_revision : svn%3Abcc190cf-cafb-0310-a4f2-bffc1f526a37/django/trunk%406711

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