fix up marshall/unmarshall of note data for MidiModel::DiffCommand

git-svn-id: svn://localhost/ardour2/branches/3.0@5662 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/evoral/src/Note.cpp

@@ -39,7 +39,7 @@ Note<Time>::Note(uint8_t chan, Time t, Time l, uint8_t n, uint8_t v)
 	_off_event.buffer()[2] = 0x40;
 	
 	assert(time() == t);
-	assert(length() - l <= 1.0/1920.0); /* acceptable tolerance is 1/ppqn. Nice if there was no magic number here */
+	assert(musical_time_equal (length(), l));
 	assert(note() == n);
 	assert(velocity() == v);
 	assert(_on_event.channel() == _off_event.channel());