[refs #131] Fixed bug where the painted debug image was used when doing board detection.
The problem was, that the global img0 Mat pointed to the same data as the camera_frame Mat in Scanner.cpp, which got modified in line 126 with paintedWarpedImg.copyTo(camera_frame);
Merge pull request #132 from augmented-go/#131_debug_image_board_detection

[refs #131] Fixed bug where the painted debug image was used when doing board detection.