io.standard-paths.unix: Fix ifconfig test.
dlopen using RTLD_GLOBAL
unix.linux.proc: Fix length of meminfo struct on some kernel versions.
unix.ffi: Use a utility word for getting the aliases back.
environment: adding a combinator to set and unset and os-env.
io.standard-paths.unix: fixing the tests for Ubuntu.
io.sockets.secure.openssl: use must-fail-with.