* configure.in: Use the AC_ALLOCA test.

* configure.in: Use the AC_ALLOCA test.
	* Makefile.in (ALLOCA): New variable, to be set by ./configure.
	(lib-src/Makefile): Edit the value of ALLOCA into lib-src/Makefile.

	* Makefile.in (install): Print out the name of the directory we're
	copying, so people can have some idea of whether we're making
	progress.

	* Makefile.in (install.aix, install.xenix, install.sysv, install):
	Don't forget to re-create the COPYDESTS directories after we clear
	them out.

	* Makefile.in: Add autoconf cookies so that the configure
	script can comment out sections of path variable definitions to
	choose between the installable configuration and the run-in-place
	configuration.
	* configure.in: Add new option `--run-in-place', to select the
	run-in-place path definitions.

	* Makefile.in (install, install.sysv, install.xenix, install.aix):
	Make sure that each source directory exists, and is different from
	the destination directory; then, delete the destination before
	copying over the source.