Log Message:
Update py-at-spi2 to 2.8.0

* Add objectLocale property (BGO#694368).
* Stop using a deprecated method.
* Don't install the example, since it isn't compatible with Python 3.
* Support new levelbar role.
* Add a --with-python option to configure.ac.
* Fix getCharacterAtOffset.
* Export application class in the Accessibility namespace, for
  backwards compatibility.