Add Light pattern modes, basic serial control
Add Light pattern modes, basic serial control

Modes added:
CHRISTMAS_STATIC
Holds alternating Red/Green/White pattern along the whole strip

CHRISTMAS_STREAKS
Same alternating Red/Green/White pattern but LEDs appear in pseudo-random
order and decay with time. NOTE: The LFSR is broken--doesn't cover all 255 states,
needs fixing.

Modes are selectable by sending 'm' to the UART Receiver.
Intensity is adjustable by '+' or '-' to UART Rx.

fictivelogic/le-lights