Merge pull request #759 from Wolf-DL4YHF/master

kludge to get backlight and app-menu running in KD4Z VM SysTick_Handler now declares being "open for business" (e.g. allows to open the new 'red button menu') even if the original draw-statusline-hook (in display.c) has never been called. That happens several seconds after power-on, similar as done in the very first version with the red-button-menu (aka app-menu). If this kludge gets the red-button-menu working with the VM again, the reason may be an outdated display.c (but the temporary fix is in irq_handlers.c) . Will test this in KD4Z VM now ...