JACK Transport reposition
JACK Timebase slave: sync to JACK tempo
Changed Preferences->I/O ui, added 'Use JACK Transport' and 'Timebase Master'
JACK driver: change preferences without unload
JACK restoring audio connections
Bug fixes
Improve bar line Inspector and Palette

**Inspector**
- Align span combo item names with palette names
- Add a [Custom] span item: it is informative only, cannot be selected and is set by the Inspector for spans which do not match any built-in span
- Implement proper selection of span combo item when a bar line is selected in the score
- Enable/disable type combo items according to bar line type (repeats cannot be turned on/off for individual bar lines)
- Implement spanTypeActivated() to set in the score the span selected in the Inspector

**Palette**
- Labels for styles and spans made clearer (hopefully...)
fix #28041: image z-order
remove MScoreText from mtest resources, seems to fix the tests
Merge pull request #1063 from lvinken/musicxml-fixes

Musicxml fixes
add missing dynamics in palette
fix #28236: Crash when you drag-drop a barline in the last measure
link section break in parts
fix spanner handling when creating linked stave
Add spacing between elements
update mtest
fix tie creation when generating parts
update mtest
Merge pull request #1062 from vgstef/ContinuousPanel

Add spacing between elements
Merge pull request #1035 from Igevorse/jack-transport

Jack transport: new features added