Added Ping, Announce and CalculateCalibration (as stub) service.
+ Created Message sender
+ Listening to System Topic
Made position module activate all cameras for calibration.
Calibration images are now saved to disk.
Checking pictures for chessboard with opencv before saving them for calibration.
Don't send bad pictures.
Added raw position callback.
Merge remote-tracking branch 'origin/master' into savingdata
Some changes to make master compile