Added an include for the memcpy function (string.h)

Fixed cmake find script.

Findusb_i2c_adapter.cmake

 #edit the following line to add the librarie's header files
-FIND_PATH(usb_i2c_adapter_INCLUDE_DIR <your own header files> /usr/include/iridrivers /usr/local/include/iridrivers)
+FIND_PATH(usb_i2c_adapter_INCLUDE_DIR usb_i2c.h /usr/include/iridrivers /usr/local/include/iridrivers)
 
 FIND_LIBRARY(usb_i2c_adapter_LIBRARY
     NAMES usb_i2c_adapter

src/usb_i2c.cpp

 #include "usb_i2c.h"
 #include "eventexceptions.h"
+#include "string.h"
 
 CUSBI2C::CUSBI2C(const std::string &adapter_id)
 {