0.6.12.18:

0.6.12.18:
	added code to initialize *DEFAULT-PATHNAME-DEFAULTS*,
		to start making it a little more ANSI
	started documenting visible-in-the-interface variables
		whose old values are discarded when a core is saved
		and loaded (e.g. *DEFAULT-PATHNAME-DEFAULTS*)
	tweaked side-effectful-pathnames.test.sh so it
		accepts the new more-ANSI behavior of
		*DEFAULT-PATHNAME-DEFAULTS*
	hacked LOAD to physicalize pathnames before merging them,
		to work around apparent MERGE-PATHNAMES problems
		and let tests/filesys.pure.lisp work with new
		nontrivial *DEFAULT-PATHNAME-DEFAULTS*; also
		hacked COMPILE-FILE-PATHNAME similarly
	factored out DEFUN PHYSICALIZE-PATHNAME
	made FILE-LENGTH "work" (up to 32 bits) on OpenBSD again