Updates to FreeIMU to correct getQ_simple reference and interface with C...

Hi Paul
Fixed the reference error that daimon posted in forum and also fixed an error with FREEIMU_FREQ not reference: Error: FreeIMU_serial:48: error: 'FREEIMU_FREQ' was not declared in this scope - Added additional F_CPU options plus case for unknown frequency to avoid future problem.

Also, in order for the serial sketch to be compatible with the python code I had to change several int * to int16_t * in the sketch and the FreeIMU.h and .cpp file which necessitated a myriad of changes if the adxl345, itg3200 and the HMC58X3 libraries.  I tested the code with a Sparkfun 10724 IMU.

If you think people would be interested I can further modify for the MPU-9150, MPU-9250 and the ALTIMU-10 boards.

v/r
Mike