Get rid of old modal types
Get rid of old modal types

Fixes TryGhost/Ghost-UI/issues/17

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