Implementation of contextual tooltips

1) add tooltips for CHANGE, ADD, DELETE, MOVE actions
2) add adapter for semantic object to compute labels
3) add unit tests

Change-Id: I808c8931e79fc4e10ea0778272b8478e6b1340e0
Signed-off-by: Mathieu Cartaud <mathieu.cartaud@obeo.fr>
36 files changed