This commit includes a method to init the a11y support. Two main purposes:
* Register the different Atk factories.
* Ensure that there are a AtkUtil implementation class available.
Part of CB#2097
The Clutter Accessibility Library is an implementation of the ATK,
the Accessibility Toolkit, which exposes Clutter actors to accessibility
tools. This allows not only writing accessible user interfaces, but also
allows testing and verification frameworks based on A11Y technologies to
inspect and test a Clutter scene graph.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2097
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>