Fixed #12840: mark natural key serialization in the docs as new in 1.2. Thanks, ramiro.
Fixed #12840: mark natural key serialization in the docs as new in 1.2. Thanks, ramiro.

git-svn-id: 554f83ef17aa7291f84efa897c1acfc5d0035373@12432 bcc190cf-cafb-0310-a4f2-bffc1f526a37

svn2github/django,svn2github/django,svn2github/django