OpenBSD/pkg_tools: check for empty -Q query
fix `make install` so it works with non-gmake `make`
we have to export PKG_PATH or else it just tries it's best to use a mirror.
not all versions of `file` output 'shell script'; but they do use the word script.
add -RN and -Rns, handle empty -Ss query properly.
Merge remote-tracking branch 'remotes/somasis/ng' into ng
README: add #pkg_tools support