Author: Stéphane Graber <stgraber@ubuntu.com>

Use ubuntu/ubuntu instead of root/root by default.  Stop
removing tty[56].conf in Precise.  Stop messing with dhclient.conf.
Set devttydir on Precise to /dev/lxc to allow for clean upgrades.
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Signed-off-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>