Fix memory leak

Fix memory leak

* Release memory before pointer overwrite.
* Free memory before overwrite pointer.
* Memory leak with ref_accessible.
* Leak in atspi_state_type_get_type.
* Remove memory leak in
  atspi_event_listener_register_from_callback_full.
* Reduce memory leaks reported on program exit.
* This api is unused by efl but still let's fix it.

Change-Id: Ifde65dd44643f2e58442cf70809703f979436e09