Move common/2d/bitblt.c -> common/2d/bitblt.cpp
Move common/2d/bitmap.c -> common/2d/bitmap.cpp
Move common/2d/box.c -> common/2d/box.cpp
Move common/2d/canvas.c -> common/2d/canvas.cpp
Move common/2d/circle.c -> common/2d/circle.cpp
Move common/2d/disc.c -> common/2d/disc.cpp
Move common/2d/gpixel.c -> common/2d/gpixel.cpp
Move common/2d/line.c -> common/2d/line.cpp
Move common/2d/pixel.c -> common/2d/pixel.cpp
Move common/2d/rect.c -> common/2d/rect.cpp
Move common/2d/rle.c -> common/2d/rle.cpp
Move common/2d/scalec.c -> common/2d/scalec.cpp
Move common/3d/clipper.c -> common/3d/clipper.cpp