transpose & render unrecognized chords
token-based rendering & other improvements
simplify and improve parsing and rendering of parens and commas
add hidden style option to suppress loading of chords.xml
add facility to define rendering by token in chord description file
add class attribute handling to token declarations
save token definitions as part of chord list
revert Jazz Lead Sheet to go back cchords_muse for now
fix handling of 0 for half-diminished
fix for scores that change from old-style chord description to wysiwyg
fixes, and change NULL to nullptr for now
nullptr => 0
fix biab import and test

Scores created via bb import were saving empty <name> tags, which was
not ideal.  They now create valid <name> tags.  Test was not expecting
any <name> tags at all, so it has been updated.
fix parts test

Scores now record <name> tags for <Harmony> objects, so references in
tests updated to reflect this
Add Harmony::render() for a QString
Fix 21162 - When a chord is removed ties to it remain behind and attach to casual notes

Fixed in RemoveElement::RemoveElement() by handling Chord's Notes tieBack

Also removes tieFor in a cleaner way.
fix #16047
Merge pull request #363 from MarcSabatella/12179-handle-unrecognized-chords

12179 handle unrecognized chords
Merge pull request #369 from softins/render-qstring

Add Harmony::render() for a QString
Merge pull request #370 from mgavioli/Fix_21162_ties_left_behind

Fix #21162 - Remove ties to notes of a removed Chord