Incomplete re-layout when the group of a staff is changed.

If a staff type ids changed from one group to another (like standard <=> TAB), lines or frtes and strings for notes are not recalculated.

Fixed by adding a call to `Score::cmdUpdateNotes()` to `ChangeStaffType::redo()` and `::undo()` when the group of the staff type changes.
Merge pull request #995 from mgavioli/Incomplete_relayout_on_staff_group_change

Incomplete re-layout when the group of a staff is changed.