Spike swing gui
Hack wire up the gui
Move tick count into workout loop
Read pause/unpause commands from the control channel
Pause/unpause on key press

Interesting delay effects when unpausing during an event sequence
Consume ticks while paused

Otherwise the user experience on resume is hilarious
Count down activity time, simplify work loop

Instead of building a tick schedule ahead of time, simply modify the
state of the current activity in the work loop.