* oln/types/optraits.hh: Add temporary fix for debug.
	* oln/types/typetraits_builtins_bool.hh,
	oln/types/optraits_bool.hh, oln/types/debug.hh: New files.
	* oln/io/pnm_write.hxx, oln/io/pnm_write_common.hxx,
	oln/io/pnm_read.hxx, oln/io/pnm_read_common.hxx: Adapt to new types.
	* oln/types/all.hh: Add includes for new files.
	* oln/types/optraits_bin.hh: Add zero(), unit(), inf(), sup(), min()
	and max().
	* oln/types/bin.hh: Add default constructor, change stream operator
	and set storage_type to bool.

    prcs2git-id: 0_5.60