Bug: Jump-start flashes channels that should remain off on dual-channel lights under some circumstances (example fix attached)

[fwiffo]

If you're in tint-autoramp mode and enter moonlight mode, both channels will flash briefly due to jump-starting. This is because jump-starting is implemented assuming a single-channel configuration. The PWM value may be zero for some channels at floor level, but not at the jump-start level.

The fix is to handle jump-starting within the multi-channel logic by computing any blending based on the "real" level and then jump-starting only those channels that have resulting non-zero PWM values. I've implemented a prototype fix for the 2-channel Emisar (model 0135), which is the only light I have to test on. I can create a more complete implementation if there is interest: fwiffo@c3d9321