Add Button Function : off+go#320

Hello,

to be able to turn off front-light during special effects it would be nice if MFF buttons can be configured as off+Go.

Example:
Button 1: Enable Strobe effect on moving heads
Botton 2: Disable Frontlight (While corresponding fader stays at100%)

Releasing button 2 wil put the front-lights back-on.

Would being able to set the flash % help here? eg. set the button of the frontlighting to flash, set value to 0% - now when you press the button, the lights go to 0%, when you release they come on immediately again?