resolv.conf handling: resolve symlink inside chroot + drop resolvconf from 96-apt...

resolv.conf handling: resolve symlink inside chroot + drop resolvconf from 96-apt-listbugs

When resolving the symlink on a system using
/lib/init/rw/resolvconf/ for resolvconf files but the chroot uses
/run/resolvconf then the readlink call from outside the chroot
fails.

| # readlink -f /var/lib/jenkins/workspace/grml64_sid/grml_chroot/etc/resolv.conf
| /lib/init/rw/resolvconf/resolv.conf
| # chroot /var/lib/jenkins/workspace/grml64_sid/grml_chroot/ readlink -f /etc/resolv.conf
| /run/resolvconf/resolv.conf

Also drop the resolvconf code from 96-apt-listbugs.
It's too error prone (meeeeeh) so people are supposed to either
have something like dnsmasq running on the host or have a proper
/etc/resolv.conf prepared.