CLEANUP: non-pointer return type for Plane::binary_adaptive, Plane::binarize:dither, Plane::dilate, Plane::weighted_sum, Plane::blur_box, Plane::gaussian_kernel, and Plane::deconvolve_rl #18
CLEANUP: Return non-pointer plane in scaling methods
FIX: do ref here, get the real object
CLEANUP: use non-pointer return type for plane edge-detection. #18
CLEANUP: remove pointer returns from cropping, level and normalize
CLEANUP: Use non-pointer return in ARender::render and ARenderPipe::render. #18
CLEANUP: Simplify RenderOperations by adding a coping version of apply_operation.
CLEANUP: Use non-pointer versions of Plane and ImageEx for caching in MainWindow. #18
CLEANUP: Switch to a Kernel type to further reduce pointer handling. #18
CLEANUP: Remove pointer based planes in RecursiveAligner