Use the tempo CV/Knob as Clock+Slip Input

[wraybowling]

I now am more confident that it will be possible to use the tempo cv and knob as the clock input.

• use the highest value for incoming clock pulses
• make use of lower range to slip the beat's offset (can be used for swing) 1 quarter note's worth?
• make use of the lowest value for disposing of the current tempo and switching to internal clock mode maintain internal clock when no external clock is used #10 until an incoming pulse is detected again
• make use of lower range values for setting tempo manually in internal tempo mode

bonus points:

• detect double-tap for catching retrigger from a host tri-ger