*  Fixed MCP23008 and MCP23017 getState() return values  
  *  Added support for MCP23S17 GpioProvider
  *  Added support for Pi-Face GpioProvider 
  *  Added support for Pi-Face Device Interface 
  *  Added MCP23S17GpioExample sample code    
  *  Added PiFaceExample sample code 
  *  Added WiringPiSPIExample sample code    
  *  Added LED component interface and GpioLEDCompoment impl    
  *  Added GpioSwitchCompoment impl