Fixed #14903 -- Removed much of the code in django.core.servers.basehttp that…

Fixed #14903 -- Removed much of the code in django.core.servers.basehttp that was previously copy-pasted from the wsgiref module which was added to Python 2.5. Many thanks to maxbublis and aaugustin.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16288 bcc190cf-cafb-0310-a4f2-bffc1f526a37