Optimization + new Hour Feature.

As promised.

Here is the pull request with the hour feature of taking a limb or healing it.

I also took the time to optimize a little the code and to use more the accelerometer in the calculation of the XP given because when reaching level 19 ... it was quite hard to continue to get XP.

Your formula for the XP_needed had a mistake that I corrected, I now display how much XP is needed for the next level.

I bumped the version to 2.40.