Initial implementation of a Range element to display a tune range
Draw line from note centre to note centre
Add support for (editable) accidentals for top and bottom note heads.

Add "Update Range" button in Inspector.
Rename to Part Range
create soundfonts and sfz directories if they do not exist
Renamed element to "Ambitus"
Moved dragable symbol from master palette's "Note heads" sectin to "Lines" section.
Merge pull request #567 from mgavioli/part_range_element

A new element for part range indication
add ScoreFont to Symbol class; extend master palette symbols dialog; misc cleanups
merge Ambitus
hide noteHeads array
fix mtest
remove QtTraceMsg
add vtest for note heads