Drum score tremolos

[brian-math]

Here's a drum score with tremolo marks (2-stroke roll) on some of the stems, which are not yet recognized by Audiveris.

[BTW, if anyone knows this song well, you may notice that the hi-hat groove is not transcribed quite how Steve Gadd plays it. He plays a couple of the hi-hat notes with the foot pedal instead of the sticks. The transcriber apparently found it a lot easier to play all the hi-hat notes with the sticks.]

Main problems on p.1:

• the tremolo marks are detected as beam hooks (but not linked to anything else)
• at REDUCTION, a lot of valid beams disappeared, along with several of the tremolo "beam hooks"

To Do: Recognize tremolo marks

50_Ways_To_Leave_Your_Lover_-_Paul_Simon-Drumset.pdf .

Originally posted by @brian-math in https://github.com/Audiveris/audiveris/issues/33#issuecomment-1089621505

[hbitteur]

Tremolo marks are implemented in 5.3 Should we this issue?