Click for A, Press and Hold for B

I planned to add a time setting mode to the alarm clock later, as gravy-- thought I wouldn't need one since the clock chip keeps time-- but with the board not yet built, I keep accidentally disconnecting the DS1307's battery and needing to reset it with a special sketch.

That's a pain, so I'm adding it to the PPAC program next, and to keep the interface simple-- jog/shuttle and a button-- a press and hold event seems appropriate for switching into an otherwise hidden mode, like shutting down a MacBook by holding down the button instead of just clicking it.

Despite a few posted examples on debouncing a button press (explicitly or with a library), I couldn't find any press+hold examples, so I took a stab at it and got a test sketch working pretty quickly with a button and two indicator LEDs. The code is posted below, as a comment.