Finished abstraction work on BeatPathSet

Signed-off-by: parhamfh <parhamfh@kth.se>
Fixed bug with assignment to property in newstyle class.

BeatPath was previously not inheriting from object and was therefor not a newstyle class. In oldstyle classes you can assign to properties without using property setters. shameful.

Signed-off-by: parhamfh <parhamfh@kth.se>
updated this too ofc, see previous commit.

Signed-off-by: parhamfh <parhamfh@kth.se>
Fixed check for notes crossing bar lines.

Should be a working implementation, from my tests it works. 
Printing is NOT working yet.


Signed-off-by: parhamfh <parhamfh@kth.se>
Fixed erroneous conditional

Signed-off-by: parhamfh <parhamfh@kth.se>
Good exampe of mock data.

gives a nice set of notes which can be used to test
the lilypond score generator.

Signed-off-by: parhamfh <parhamfh@kth.se>
Properly prints a .ly-file with bar lines.

The score will be correct and the included bar lines will check that there is no overflow or underflow of note values.

Signed-off-by: parhamfh <parhamfh@kth.se>