Merge branch 'ps/ban-a-or-o-operator-with-test'

Test and shell scripts clean-up. * ps/ban-a-or-o-operator-with-test: Makefile: stop using `test -o` when unlinking duplicate executables contrib/subtree: convert subtree type check to use case statement contrib/subtree: stop using `-o` to test for number of args global: convert trivial usages of `test <expr> -a/-o <expr>`