Added 'Committing code' section to docs/contributing.txt and made a few cleanups
Added 'Committing code' section to docs/contributing.txt and made a few cleanups

--HG--
extra : convert_revision : svn%3Abcc190cf-cafb-0310-a4f2-bffc1f526a37/django/trunk%401857

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