Further improve various Phame UI things

Summary:

• Better icons and action order.
• "Move Post" action.
• (Bugfix) Allow multiple blogs to be set to not having custom domains.
• Make "Write Post" skip the "select a blog" step when coming from a blog view.
• Sort blog list on "Write Post".
• Show messages when a post is a draft or not on a blog.

Test Plan: Created posts, blogs, moved posts, preview/live'd posts, etc.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1373

Differential Revision: https://secure.phabricator.com/D3708