fix default timesig
capx slur support
Implements persistent state of piano keyboard (PianoTools class)

*) PianoTools is unconditionally created at startup (like palette and inspector), so that saveState() and restoreState() can manage it
*) Shown/hidden state is stored into / read from QSettings
fix #20954: Brackets drawn incorrectly in Gonville
update note groups dialog
Merge pull request #327 from mgavioli/PianoKeyboard_persistent_state

Piano Keyboard: persistent state
remove playpanel dependency from sequencer
fix aeolus installation
Merge pull request #323 from lvinken/20581-capx-impl-3

20581 capx impl 3
fix #20880
fix sequencer setPos()
another try in fixing the seq