Added pairing support to a fork of the library

Hi

I hope you don't mind, I took a fork of your library and extended it to support a pairing button, and storing paired remotes in the arduino eeprom. I also included a new example .ino file that demos the pairing support, it adds a dimmable output to pin 9 , that only paired remotes can control.

Here are the commit logs for the fork:

Added support for pairing Lightwave RF remotes and switches with the
Arduino. Up to 6 switches can be stored in the EEPROM, there is also
functions for removing the pairing.

Added a new example to demonstrate the pairing functionality. Connect a
button to pin 4 to pair, pin 5 to clear. pin 9 is PWM'd