Notification cleanup
Notification cleanup

Closes #666.

* Adding new error notifications (removed post name, cleaned up statuses) when creating/updating a post
* Removing scheduled from the maps and changing the text of publish-on
* Made temporary "Scheduled publishing is not supported yet." message display in a proper error container, plus a slight grammar fix.
* Removed ; from the start of validation errors on post error, as the previous sentence finishes with a .

TryGhost/Ghost,TryGhost/Ghost,TryGhost/Ghost