* apps/generic-skel/image3d-skel-with-end-points.cc
	(load_pgm_3d, save_raw_3d, subsampling_3d, draw_torus):
	Move functions...
	* apps/generic-skel/image3d-skel.hh: ...here (new file).
	(make_triple_torus): New function.
	* apps/generic-skel/Makefile.am (noinst_HEADERS):
	Add image3d-skel.hh.