Visually combines pairs of notes across a bar line in a single cumulative note value.

Used in early music, usually together with mensurstrich.
Hide ledger lines
Notes merged into value of previous measure should not combine their hook/beam with following chord beam.
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Align with recent re-factoring.
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fix default timesig
capx slur support
fix #20942: Changing font from Emmentaler to Gonville doesn't update time signature
fix #20943
fix crash in timesig properties dialog
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