Make sure chroot building do not start any services.
Instead of stopping the ssh service after configuring packages, add
policy-rc.d script to block any services from being started in the
first place.  This ensure apache, rsyslogd and others are not started
in the chroot during build.
Merge pull request #29 from petterreinholdtsen/policy-rc-d

Make sure chroot building do not start any services.