2009-09-30 Ivan Maidanski <ivmai@mail.ru> (really Petter Urkedal)

2009-09-30  Ivan Maidanski <ivmai@mail.ru> (really Petter Urkedal)

	* configure.ac: Rewrite the tests for external or internal
	libatomic_ops.
	* configure.ac: In particular, drop the symbolic links. Add option
	--with-libatomic-ops for forced selection.
	* Makefile.am: Adjust the path of source files from libatomic_ops
	to not use the links.
	* Makefile.am (libgc_la_LIBADD): Add $(ATOMIC_OPS_LIBS). This will
	be empty if we use the bundled AO sources.
	* configure: Regenerate.
	* Makefile.in: Ditto.