allow access to the wiringPi to BCM_GPIO pin mapping tables.

hardware revision number... So have adapted wiringPi to cope.

accomodate the changes in pin that are present on the Revision
2 Raspberry Pi board.

Added in simple debugging too - set the environment variable
  WIRINGPI_DEBUG
to get some more debug messages out

Changed the gertboard code to use it
and ran more tests on he Gertboard code.

and an example.

code. Seems the old 4011 in the NES controller isn't that fast
afterall!

to pumSetRange() happens.

ANDing with 0x3FF was wrong anyway as the PWM counter does from zero
to the top value, not top-1 as I originally thought.

Conflicts:
	gpio/gpio.c

Updated wiringPi to add new PWM controls.

Added top-level build script for lazy building.

in pinMode ()

General tidying up of some of the code round delayMicroseconds