Chord Semantics Patch

[Charles Winston]

Hi developers,

I posted a new patch on Reitveld that captures the semantics entered in 
chordmode in order to produce more accurate chord names. The way it works now, 
the input: \chords { c:m7.1 ees } will produce identical chord names: Eb. 
Though with my patch, c:m7.1 produces the name Cm7 omit root, as it should.

The patch captures all the relevant information entered in chordmode: root, 
extension, modifier, alterations, additions, removals, bass, inversion. It 
saves this information as a ChordSemanticsEvent, part of the elements of 
EventChord. This event is iterated and passed to the chord_name_engraver, which 
uses a new naming function to produce chord names based on the semantics list.

Let me know what you think,

Charles Winston