Updated syndication framework porting notes.
Updated syndication framework porting notes.

This is based on some experience porting older code and trying to work
out why my feed content was empty.

--HG--
extra : convert_revision : svn%3Abcc190cf-cafb-0310-a4f2-bffc1f526a37/django/trunk%4012742

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