Instrument Wizard (incl. New score Wizard):

Staff type presets listed in the preset combo boxes are filtered out according to instrument data:

- if has string data, allow normal and tab presets
- if has drum set, allow percussion presets only
- if has neither, allow normal preset(s) only

Also:

Staff Props dlg box: completes filtering out of perc. staff types (and fixes two bugs!)
STAFF PROPERTIES dlg box:

Hide string data controls if the staff instrument has no strings.
Merge pull request #350 from mgavioli/Instr_wizard_filter_staff_types

Instrument Wizard: filter staff presets according to instr. data
add namespace Ms
Merge pull request #351 from mgavioli/STAFF_PROPS_hide_str_data_controls

STAFF PROPERTIES dlg box: Hide string data