0.7.12.50

0.7.12.50
	It's easier to port a shell than a shell script. -- Larry Wall

	Contrib-related fixes -
	... multiple uses of test -e are now test -f
	... don't run make test in install, it's more work than we
	    want to do as root
	... instead, touch $i/test-passed in make-target-contrib.sh
            (if, indeed, it has) and test for presence of that file
	    when installing
	... Rationalise AF-* constants in sb-bsd-sockets: AF-LOCAL
            is the One True Name.
	... In sb-bsd-sockets build, don't hardcode gcc to be in /usr/bin