Wireless connection to RFax

Everything is the same as previus post, only wireless thru raspberry on
the robot.
TODO: automatic RPI WiFi connection anywhere
RFax smarter then ever.

Follows lines, Recognises crossings, turns according to directions sent
from RPI, checks battery levels(accuracy depends on power supply). Avoid
(measure wheels) does not work anymore, because there are ServoWrites()
unincluded there.