Re-design staff props and staff type props dlg boxes.

- Staff props dlg: added type props common to all types (num. of lines, line dist., etc.).
- Changing some type props but canceling the main dlg no longer changes the staff type.
- Fixed equality checks in EditStaff::apply().
- Both dlgs: set all buddies and proper tab order.

Also:
- Staff group names ("Standard", "Percussion", "Tablature") made uniform in spelling and translatable.
- Fixed Instrument::operator==().
Updated EditStaffType. Improved EditStaff.
Align code to commits merged in the meantime.
Fix staff type group names in score files.
Align with latest enum changes
Do not select any template at EditStaffType initial opening.
Layout of score for TAB preview made more compact.
Merge pull request #937 from mgavioli/Staff_props_and_stafftype_props_dlg_box_redesign

Staff props and stafftype props dlg box redesign