XMLRPC: Introduce new create,read,update and delete XMLRPC apis for Posts,...

XMLRPC: Introduce new create,read,update and delete XMLRPC apis for Posts, Pages and all Custom Post Types.
Introduces: wp.newPost, wp.editPost, wp.deletePost, wp.getPost, and wp.getPosts
See #18429, #18430, #18431, #18432, and #18433 props maxcutler and markoheijnen.


git-svn-id: https://core.svn.wordpress.org/trunk@19848 1a063a9b-81f0-0310-95a4-ce76da25c4cd