Demonstrates a watchdog timer in run mode

Example functionality:
When the program starts LED3 blinks three times and stops.
    Then LED0 start blinking continuously.
    Open a terminal program to see interrupt messages.

    SW1: Push SW1 to trigger a watchdog reset. This will reset the watchdog before
         the wait period has expired and trigger an interrupt.

    SW2: Push SW2 to trigger a delay and see LED0 stop blinking momentarily.
         This delay long enough for the timeout period to expire and trigger an interrupt.

    SW3: Push SW3 to trigger a longer delay and see the program restart by blinking LED3 three times.
         This delay is long enough for the reset period to expire and trigger a reset.
