Added Eagle Layout Files
Removing Time.h library - now keeping track of time on my own

Time.h and TimerAlarm.h consumed 2,320 bytes of program space.  Since I
was only depending on them to track "simple minutes", I removed them and
will now keep track of time by using millis
Adjusting WARNING period LED visual

Yanking some duplicate logic out of the main loop and creating a
SHUTDOWN_WARNING_PERIOD boolean to keep track of things. Clarified the
names of some constants.  Restored the outside "if" statement of "if
(fireplaceOn)" into the countDownTimer loop as I believe it was correct
in the first place and not causing the weird issues I ran into before.
Updated logic for stop/start

Starting worked fine.  Stopping via the timer worked fine.  However,
stopping from a button press was NOT working because there was no logic
to stop the fireplace outside the countDownTimer routine.  This adds
shutdown logic in the main loop should fireplaceMinutes go to 0.
Control Panel Layout

Measured drawing of layout for control panel
Board Layout initial Checkin

Since many components will not exist on the PCB, I created a new layout
with a 16 pin header which will "jump" to the external devices.  I'll
bet Eagle can do this, but I wasn't sure.