Moved the extensions into wiringPi from gpio and made it more general purpose
more so that RTB and anything else can dymanically add devices
into wiringPi.
Changes to GPIO to updates for the SPI and I2C module loads
Added gpio unload for SPI and I2C.

Added a new way to setup SPI - by passing the mode in.

Support for the new Pi2 thing too

round at last..

Updated for the 0x0012 board revision on the new A+

of changing it for the B+)

Aded a gpio command: usbp hi/low - to change the usb power

to produce a nicer 'readall' output too.

It also understands new pins 53,54,55 and 56 in wiringPiSetupPhys()
mode to represent the pins on the P5 connector on the Rev 2 Pi's

Changes to pinMode() to allow new modes SOFT_PWM and SOFT_TONE.

fixed the max5322 code.