Changes since 3.1.1:
New comparison algorithm that ignores voicing and chording, just comparing all the notes,
wherever they are in the measure.
New command line and API that allows fine-grained setting of requested details.
New output option that prints a diff-like text description of the differences to stdout.
Support comparison of slurs.
Support comparison of chord symbols.
Better comparison of tuplets.
Better comparison of lyrics.
Ignore leading and trailing whitespace in directions, lyrics, and metadata.
Fix random crashes and long-term memory growth when doing multiple comparisons in one run.