Changed the LSM303 config behaviour to support 12-bit resolution.

Changed the LSM303 config behaviour to support 12-bit resolution.
Stopped it setting up the FIFO, as that seems to limit accel output to 10-bit.
Should probably delete the lines of code, but not sure if disabling FIFO will affect anything?

Also modified accel Set Range, so that it also sets the 'high resolution' bit. 
Is this the right place to put this? Another option is to change the #defines of the accel ranges to already include the HR bit. but then could be misleading.