[seccomp] allow also poll on the latest fedora we glibc uses poll. On the other linux distro I tried (void), musl is probably providing poll as a ppoll wrapper.

we don't need to check for CGI anymore

initial seccomp support

split into two processes: listener and executor this way, we can sandbox the listener with seccomp (todo) or capsicum (already done) and still have CGI scripts. When we want to exec, we tell the executor what to do, the executor executes the scripts and send the fd backt to the listener.

sandbox also on FreeBSD with capsicum