Correct wind direction reading from the anemometer

It's has a 90 degrees offset due to our awesome setup :-)
DataLogger: separate csv fields by semicolon
DataLogger: don't add newline twice
Revert "GPS_library_absolutepath"

This reverts commit 5c2eca1bc1d72efa57d641e38ee65ae7bb542269.
Remove local copy of Adafruit_GPS library

We will use it from the global library path
Add submodule for Adafruit_GPS library
Add submodule for RTClib
Add submodule for Adafruit_BMP085 library
Add submodule for SHT1x library
Add a small README about library management
Implement the motor driver
Implement very simple sun position estimator
Implement SolarPanelPositioner
Use pin 50 for ENABLE of the L293
Remove obsolete pin definitions
Use different pins for SHT15
SolarPanelPositioner: stop motor when we are orientation
Define and use a DEBUG_SERIAL