* doc/examples/ima-save.cc: Add a FIXME.
	* doc/examples/ima-load.cc: Likewise.
	Avoid hard-coded paths.
	* doc/examples/tuto4/image.cc: Make it compile.
	* doc/img/small.pbm: New symbolic link to img/small.pbm.
	* doc/examples/split/ima-load-1.cc.raw: Regen.
	* doc/examples/fill-imageif-cfun.cc,
	* figures.mk,
	* ppm-figures.mk:
	s/fill-subimage-cfun/fill-imageif-cfun/.