Jukebox Applet Fall-through Buttons

[travisgoodspeed]

Since the Jukebox app was first written by @notpike, the third row of buttons has become a "fall-through" row, which calls the submenu applet if pressed from the clock. This is mostly used by the Hebrew calendar and the Beats clock, but it could also be handy if you want to be able to skip songs at the bar with one press from the clock and no mode switch.

I've power profiled this to make sure that the radio is turned off, and the code looks right. I'll try it out on a real jukebox before merging.

• [ ] Test on a real jukebox.
• [x] Pin selection is persistent, only changed from 000 with Set button.

[notpike]

More then glad to help with QA as well.

For the most part people leave their jukebox's set to 000 and I've only ran into one that used something different. I don't think it would take away from this app to hard code the PIN at 000 but I'm going to still use this feature for my firmware. :3

[travisgoodspeed]

I think this is good go. The behavior changes like so:

1. The Jukebox app no longer asks for a pin on entry, or clears the pin to 0 on exit.
2. Press the Set button inside of the app to change the pin.
3. The full keypad is still available inside the app.
4. In the Clock app, while Jukebox is selected, press 1 to Pause, 3 for Power, and - to Skip. 2 is available for a submenu action, but is not currently assigned to anything.
5. Clock uses a ton of power while transmitting, but always seems to always drop back to something appropriate afterward.

I should be able to test this on a live jukebox either tomorrow or Thursday. Will merge after it's verified.