Add nodes selection facilities

- deselect and disable All ResultNodes when the direct parentNode is
deselected,
- deselect and disable the parentNode if all its children are deselected
- select and enable the parentNode if all its children are selected
- select and enable ancestors if one leaf has been selected 


Change-Id: I91d184b589660f6991037a8eb0ffe9d4ed4015f9
Signed-off-by: marwa rostren <mrostren@obeo.fr>