Restored documentation about pickling QuerySets (and how to only pickle the

details for the query, rather than the results) from r7499.

These were accidentally nuked in the docs refactor. We know who the offenders
were. They will be made to sit in the corner on the naughty mat for a while.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@9090 bcc190cf-cafb-0310-a4f2-bffc1f526a37