wiringpi2 2.0.0

WiringPi library wrapper for the Raspberry Pi only. Wraps up version 2.x of the Arduino wiring-like WiringPi library into a convinient Ruby gem. Currently includes GPIO functionality, I2C, SPI, serial and shiftOut/shiftIn support in addition to peripheral drivers for things like the MCP23017. Credit to Gordon for the WiringPi library, which can be found here: http://www.wiringpi.com