Simplify the Ubuntu template a bit
Simplify the Ubuntu template a bit

     - Update list of extra packages for debootstrap to only include vim
       and ssh. The others were only relevant when we were still using the
       minbase variant. (LP: #996839)
     - Drop any hardcoded Ubuntu version check and replace by feature
       checks instead.
     - Format lxc-ubuntu to consistently use 4-spaces indent instead of
       mixed spaces/tabs.
     - Update default /etc/network/interfaces to include the header.
     - Update default /etc/hosts to match that of a regular Ubuntu system.
     - Drop support for end-of-life releases (gutsy on sparc).
     - Make sure /etc/resolv.conf is valid before running any apt command.
     - Update template help message for release and arch parameters.
     - Switch default Ubuntu version from lucid to precise.

Signed-off-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>
Signed-off-by: Serge Hallyn <3df611b026e4639bee8aef7a4beb2e39fcebb313@ubuntu.com>

ostap/lxc,ostap/lxc