Handle layoutChanged signal

This implements basic handling of the layoutChanged signal that may
be emitted by some Q models in LRC. This does not handle all the
cases, but it should not cause any crashes.

This should allow us to use the filtering and sorting features of
QSortFilterProxyModels.

Change-Id: I4ae590b6ab9adea75335d6fd4eb71354168e0ba1
Tuleap: #651
1 file changed