* configure.ac (VCSN_ARG_PROGS): New.
	Use it.
	* include/vaucanson/xml/xerces_parser.hh,
	* include/vaucanson/xml/xerces_parser.hxx:
	Don't rely on VCSN_XSD_PATH, but only on VCSN_DATA_PATH.
	Don't define macros in lower case.
	Make them short lived.
	* src/vaucanson.mk: Adjust.
	* doc/NEWS.txt: Document it.

	* doc/manual/developer.tex (Use of Macros): New.

	* Makefile.am (README, NEWS): Make them read only.