Show validation error when saving post
Show validation error when saving post

Show the model.validationError if one is present and also coalesce the
empty title for a more meaningful message.  Also, reset the button text
after failure.

acburdine/Ghost-Admin,kevinansfield/Ghost-Admin,airycanon/Ghost-Admin,dbalders/Ghost-Admin,TryGhost/Ghost-Admin,JohnONolan/Ghost-Admin,TryGhost/Ghost-Admin,airycanon/Ghost-Admin,kevinansfield/Ghost-Admin,dbalders/Ghost-Admin,JohnONolan/Ghost-Admin,acburdine/Ghost-Admin