NOOP, format default-config values
update ghost track colors:

'clip' and 'wave' need to have the same value,
since only either of them is painted.

desaturate background and show some wave-fill.
fix crash when importing midi files with >1 midi-channel -- fixes #5965
fix CPI window handling:

Move control-surface editor-window management to the control surface.
The Preferences-Dialog is not aware of session specific or surface
specific actions and cannot properly manage the window.