TinyMCE: fix error trying to translate non-existent button "title" in the compat3x plugin. See #24067.
Built from https://develop.svn.wordpress.org/trunk@26994


git-svn-id: http://core.svn.wordpress.org/trunk@26871 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Autosave: refactor autosave.js, use heartbeat for transport and move all "Add/Edit Post" related functionality to post.js. See #25272.

Built from https://develop.svn.wordpress.org/trunk@26995


git-svn-id: http://core.svn.wordpress.org/trunk@26872 1a063a9b-81f0-0310-95a4-ce76da25c4cd