Fix forward declaration
[ #34339 ] Cleanup in ContactDock destructor

One of the dock is causing a SEGFAULT. The Contact or Call ones are the
most likely to be the problem source. The backtrace on the mailing list
is not clear.
Fix mem leak. Not check pointer before delete it
Const'ref. Not necessary to check pointer before to delete it
Dead code elimination
Notify PhoneNumbers if their account is deleted
Room tone -> dial tone
Fix 079f9d2
Ignore 'x' value when painting categorized delegates, directly use theme metrics
const'ref. Don't check pointer before to remove it
const'ref
Document contact delegate