Added doxygen configuration file to repository.

Signed-off-by: Vinicius Gardelli <gardelli123@gmail.com>
Added /doc folder to gitignore.

Signed-off-by: Vinicius Gardelli <gardelli123@gmail.com>
Removed PCCore prefix from Chessboard, CameraCalibration and CalibrationHelper class names.
Extracted Chessboard, CameraCalibration and CalibrationHelper classes to separete files.

Signed-off-by: Vinicius Gardelli <gardelli123@gmail.com>