Updated sensor to produce degrees and radians

Formated convert functions to make more sense, and used Gravity and Pi
as an outside constant defined in the newly created file called
included/dashee/constants.h
Use atan2 instead of atan, mistake! fixed.
Debug from the accelerometer removed

For debugging I created a radian2() function inside the
AccelerometerADXL345 class. However I forgot to remove this.

The playground script now uses better formatting to help with reading
the continuous values from the sensor.

The tests have segmented UpdateAndRead to use their own functions for
scale type. It helps to debug things when they go wrong as we know what
scale we are running at.
Accelerometer Dummy needed to change the function name.

changed testReadAndUpdate to testUpdateAndRead because the Base class
implemented method throws an exceptions
Merge branch 'sensor' into testing