Reverted the `open_interface` name changes.
Removed calibration data from the repo, and added the directory
which will hold this data on local repos to the `.gitignore` file.
Converted all 4-spaces to tabs in c-files to make consistent style.
Fixed quick refactoring oversights.
Added LCD warning when attempting to initialize OI.
Started debugging `Rover.scan()`.
Collected proper distance calibration data.
Merge pull request #15 from dwtj/master

calibration, OI stuff