Add functionality to samples to only update our Scene data structure
when a new asset has been added. Also add callback mechanism for when
the object is done being added to the scene. Previously, the
scene was reinitialized on each addasset call.
Remove redundant notification.
Add subchannel instead of a new channel.
Merge pull request #14 from lagoa/mrafsan/feature/add_object_update

Mrafsan/feature/add object update