Made `MultiValueDict`'s `get` and `getlist` method docstrings more descriptive.
Made `MultiValueDict`'s `get` and `getlist` method docstrings more descriptive.

--HG--
extra : convert_revision : svn%3Abcc190cf-cafb-0310-a4f2-bffc1f526a37/django/trunk%406714

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