UI: Save and "Post created successfully"

[wolfgangw]

Sorry, no pull request but merely some UI feedback: Personally I'd much prefer a dirty state of the save button or, rather, autosave. Also the flash "Post created successfully" (which bumps down the main part of the page) doesn't really do anything for me. Why not reduce the whole save mechanism to autosave and save/post whatever is dirty both for preview and admin? Drafting, after all.