Check that the ID is valid for every endpoint

git-svn-id: http://gsoc.svn.wordpress.org/2013/rmccue/trunk@2264 f69abe3c-2ee2-4550-9a6d-17bd458115be
Goodbye fields, hello context.

See #328.

git-svn-id: http://gsoc.svn.wordpress.org/2013/rmccue/trunk@2265 f69abe3c-2ee2-4550-9a6d-17bd458115be
Ensure the post endpoint object is global

git-svn-id: http://gsoc.svn.wordpress.org/2013/rmccue/trunk@2266 f69abe3c-2ee2-4550-9a6d-17bd458115be
Add page support

See #271

git-svn-id: http://gsoc.svn.wordpress.org/2013/rmccue/trunk@2267 f69abe3c-2ee2-4550-9a6d-17bd458115be
First pass at media

See #272. This has been a long time coming, and it's finally at a point where
I'm happy to push it out. Good luck.

git-svn-id: http://gsoc.svn.wordpress.org/2013/rmccue/trunk@2268 f69abe3c-2ee2-4550-9a6d-17bd458115be
Ensure the author always exists

git-svn-id: http://gsoc.svn.wordpress.org/2013/rmccue/trunk@2269 f69abe3c-2ee2-4550-9a6d-17bd458115be