Cleanups:
1. Do not modify container's /etc/hosts (archlinux uses /etc/nsswitch.conf)
2. Remove duplicate lines from config
3. Print a nicer final message
4. Get rid of some grep's in favor of bash regex
Signed-off-by: Leonid Isaev <lisaev@umail.iu.edu>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>