Calling `'That's all at handstroke'`

[centreboard]

'That's all at handstroke' becomes Change method in the RR audio

~1) Update RR to use That's all audio~ 2) Edit the call to just emit That's all when processed by ComplibCompositionGenerator

[kneasle]

I like option two more - this is a side effect of using an API designed for Handbell Stadium, and hopefully people will notice the super early That's All and stop at handstroke anyway. ~That reminds me actually, we should probably stop Wheatley from leaving the bells up at handstroke if --stop-at-rounds is set...~ Snap I had not seen your PR...