Float2 integer faster processing.

1. Replaced float with integer, should be faster  
Added Wilco_sqrt as integer function and removed all other usage of float.
Should also increase speed significantly. (I.E. reduce battery consumption.)
Side benefit is reduction of 2KB code of float emulation routines.
2. Reduced sampling rate
I think it used default 25Hz, with reduction to 10Hz, we do not lose accuracy as the sampling is none every 100Ms anyway.

In addition I think, it's better to remove timer and activate the calculation and screen update from accelerometer event that is 10 times per sec anyway. (just change num_samples	to 1)