Prepare human beat functions
Add Beatroot code by Simon Dixon for beat detection in MIDI files

1. Passing of objects by values into functions
   were replaced by passing them by reference, where it is worth it.
2. Code style was reformatted according to the MuseScore style

Reformat Beatroot code style

Conflicts:
	mscore/CMakeLists.txt
	mtest/CMakeLists.txt
Fix fillBeats function (Beatroot): no interpolation between 1st and 2nd beats
Make the scope of local variable more narrow (Beatroot)
Integrate Beatroot (beat detection) algorithm into MIDI import