crappy quality ezjail replacement


This is a fairly crappy replacement for ezjail which nullfs-mounts every
relevant directory from / directly into the jail rather than using a basejail
and then configures the newly created jail using vnet/VIMAGE to have its own
virtualised network stack and creates the relevant entries for the new
jail.conf mechanism rather than the ugly shell based rc.conf variables. Written
in perl because I expected more string mangling. Could be ported to sh.

Warning: Ugly code, but it seems to work.