January, 2008
Fully rewritten by Wilbert Berendsen

Changes:

- correctly parse pitches, chords, durations, etc. marking often made mistakes as invalid
- speed up by shortening contexts, e.g. branch out on a \, instead of RegExpr'ing all \commands
- recognize some contexts like \layout, \with, \header to colorcode variables, engravers, etc. only there
- recognize lilypond words like ChoirStaff etc. only in sections and after \set, \override etc.
- highlight some standard Scheme function names - add \figuremode recognition