Remove unnecessary note overlapping check and add Q_ASSERT instead
Fix too many tuplet voices (> VOICES)
Fix multiple voices for drum tracks
Fix !useMultipleVoices case for tied tuplets
Enclose assert functions by #ifdef QT_DEBUG
Remove incorrect comment
Add note overlap check after removeOverlappingNotes function
Merge pull request #622 from trig-ger/midi_fixes

Fixes for MIDI import