- added solo no send on MixerChannelNode
- [impl in TrackNodeTest] move logic must allow an entry to be moved if its in conflict with itself but nothing else
  - if the start is invalid AND the start is inside itself AND the end gets the same test
- added ToggleButton
- added SequencerNode transport change event
- added SequencerNodeBPMChangeEvent
- added Image to ToggleButton