clean some dialogs, make group box title bold
more options to export positions
add bottom line to groupbox, start to fix spinbox style in plugins
fix warning in editstyle.ui about zorder
mark MuseScore 1.3 files as imported file to avoid accidental override, see #27291
mark imported 1.2 files as new
fix slur command in note entry mode
fix #26731
fix #27646
fix #26476
clean up
turn enum TIMESTEP into enum class TimeStep
turn enum BEAM_MODE into enum class BeamMode
turn enum FORM into enum class Form
turn enum CLEF_LINE into enum class ClefLine
turn enum OCT into enum class Oct
replace use of unnamed enum with BarLineType
turn unnamed enum into enum class CapellaType
turn enum StemDir into enum class
turn enum CapellaError into enum class Capella::Error

leaving CAP_NO_ERROR and CAP_EOF to not conflict with system headers