Support long press of keys

[jamesgol]

Support long presses of hardware keys.

Will likely require changes to:

• Key-Editor app
• Framework code that deals with keypresses

[lkernan]

I started playing with this at one stage but gave up. It will be a pain because you can't know which physical button has actually been pressed, only that you've received a specific keycode that the MCU has been programmed to send.

I wish they'd just sent a custom values for each button and had a bonovohandle type service interpret it rather than have the MCU send key presses.