v0.3.0

• BREAKING CHANGE: Refactoring the AvatarHandler. Only if you've
  implemented a custom AvatarHandler you might need to do some changes:
  • setPointerEventsNone and resetPointerEvents were removed and don't
    need to be called any more. Pointer event styles are handled automatically.
• Fix AvatarHandler margin caching: The AvatarHandler only cached the
  margins once for every Draggable. This caused problems when margins of
  elements in the same Draggable had different margins or the margins were
  changed. Now the margins are reset after every drag.