Stabilization for heavy bus activity
Improve stability when flooding bus with MIDI clock while beating on 206e/225e preset changes. Try to release bus and wait at the first sign of trouble. Clear queued requests, and reset I2C. Lots of debugging statements added for error cases. Added an attempt to recover I2C functionality when USB is disconnected because WPM can get hung up and it seems USB connect/disconnect are the only things functioning (because interrupt based.) So user code gets hung, but not sure where.