Added interactive output selection to the tutorial.
Updated the INTRO file to reflect recent changes
added tests for the "accidental" (flats and sharps) grammar rule
added unit tests for the new interval pseudo-constants
and fixed some flawed existing tests
patterns have convenience constructors too
Made it so syntax "C:q -q D" doesn't propagate the rest to the following note events.
This was very counter-intuitive.
Merge branch 'dev' of github.com:adamjmurray/mtk into dev