Improvements to MIDI editing

Just a few things that would improve editing MIDI in the Key Editor.

  1. After Gluing events, events stay selected.
  2. Editing the velocity of a MIDI event selects the event.
  3. Drag to copy velocity values of several MIDI events to apply to other MIDI events.
  4. MIDI Part borders to Events. A quick way to resize the MIDI Part.
  5. Create Note Expression and CC curves for multiple MIDI Parts. Drawing in a curve applies that curve and CC to all MIDI Parts currently active in the Key Editor.
  6. Tabs to show/hide CC Lanes.
  7. Ability to add a lane with a simple + button.
  8. The Edit Active Part Only button works whether events are already selected or not.
  9. Range selection tool for editing a specific range across multiple parts quickly.
  10. KC for the Tilt function for editing velocities.