Fixed I2C2 initialization
Make the version-scripts git-aware

Some people prefer to use git (easy possible by using git-hg) therefor
make the version-scripts git-aware.

To not change the view of the version string(s), the version when using
git still looks the same as if mercury is used (and not like a
standard git-version).
Fixed make cload by updating references to crazyflie-clients-python