allocate Gcode objects on the heap, don't clean them up until the related block becomes unused
Merge branch 'fix/gcode_freed_while_in_queue' into edge
USB: ensure interrupts are disabled while getting LPC serial number
Events: add ON_SECOND_TICK event that fires once per second. Also finish moving event stuff to Module.{h,cpp} so it's all in one place
move on_second_tick callout to on_idle event, also provide a flag to detect interrupt context
TemperatureControl: report temperatures every second while waiting for warmup
Merge branch 'feature/on_second_tick_event' into edge