Bump version to 0.2.0a.
Merge branch 'develop' into release/0.1.x

Conflicts:
	setup.py
	vxfreeswitch/__init__.py
Only log the event name for unbound events.
Test indicating double registration deferred callback when hangup is sent before disconnect.
Make deregister_client idempotent.
Merge branch 'feature/issue-6-fix-double-callback-of-registration-deferred' into develop
Merge branch 'develop' into release/0.1.x
Version 0.1.1