Hough fine tuning
Stricter staff filter
Force odd median kernel size
Smaller Hough systems rho range

We expect an empty space of staff_dist/2 around each barline,
so we should only be able to shift the barline by that much.
Merge all possible barlines when testing system
Don't test systems with no overlapping barlines
Staff y-position calculation for staff systems
Merge branch 'systems'