LOC_CALIBRATION: location and angle can be corrected on the fly

- calibration is done by pushing buttons in Map testing -tab. One
  push does a correction by the amount of ONTHEFLYCORRECTION
- the buttons are now like other buttons. Someone should improve
  their visuals (icons instead of text) and location.
- only one Roomba can be selected when doing these corrections
LOC_CALIBRATION: Fixed angle calibration