A simpler (and yet correct in more cases) algorithm to find the direction of a broken beam.

Now finds the right direction in the great majority of cases without any attempt to 'understand' the rhythm or the time signature.
Might fail with some highly subdivided tuplets (10-plets or more) or sub-tuplets.
Merge pull request #229 from mgavioli/Broken_beam_direction_again

Fix # 19021 - Broken beam direction (again!)