Bug 559116 - GenericEditor hooks for Tree Master Detail

- add GenericEditor hook for customization of the tree builder
- add GenericEditor hook to handle activation of a detail view-model context
- add DetailPanelRenderingFinishedCallback API variant that provides also the detail view-model context that was rendered/activated

Change-Id: Ibd71c72d3f5d0de363d0fa512286425283e38320
Signed-off-by: Christian W. Damus <give.a.damus@gmail.com>
7 files changed