Drop support for ASDF 1.

Drop support for ASDF 1.

ChangeLog entries:

2012-01-16  Didier Verna  <didier@lrde.epita.fr>

	* INSTALL: Mention that ASDF 2 is needed.
	* Makefile (SYSTEMS_DIR): Remove variable.
	* Makefile (install-system): Remove target.
	* Makefile (uninstall): Drop deletion of ASDF 1 symlink.
	* Makefile (.PHONY): Remove install-system dependency.
	* Makefile.cnf: Remove documentation of ASDF 1 symlink
	installation directory.
	* com.dvlsoft.clon.asd:
	* version.cl: Use asdf:load-system directly.

2012-01-16  Didier Verna  <didier@lrde.epita.fr>

	* doc/user.texi:
	* doc/user.texi: Ditto in the examples.

2012-01-16  Didier Verna  <didier@lrde.epita.fr>

	* demos/simple.lisp:
	* demos/advanced.lisp:
	* demos/dump.lisp: Remove ASDF 1 stanzas. Use asdf:load-system
	directly.