New discovery: Contiki also uses timer 0. With almost the same interface
as Arduino. So we now completely get rid of wiring.c (only the main
file, the other wiring_xxx stay) and implement Arduino timer, delay, etc
in terms of the corresponding Contiki routines. Verified that now delay
works as expected. The LED in examples/osd/arduino-sketch blinks!
Before this, the arduino_init routine in wiring.c destroyed the timer-0
initialization of contiki, making both, contiki timer implementation
*and* contiki timer implementation fail if the arduino_init routine was
called. Now both work.
Squashed with following bug-fix commit.
c46d6afa39