What's new in at-spi2-atk 2.1.3:

* Fix for BGO#652797: Remove unused AtkMisc instance.

* Only register events when something is listening.  In theory, this should
  mitigate performance loss that might show up when no ATs are running.

* BGO#652596: Allow setting value via the DBus property again.

* BGO#652858: Deregister objects on state-changed:defunct.

* Add AT-SPI mapping for ATK_RELATION_NODE_PARENT_OF.