tailor: pass --force-confold to dpkg in installs

This option prevents "upgrade" and "install" failing if there is already
a cloudfabric.conf that differs from the old packaged conf file.
Tailor: deterministic node numbering

GDB-693 #resolve #time 1h

* Use an OrderedDict for the hostlist. This means IDs are not assigned in
  order that the hosts are listed.
* Respect "number" property if set.
* Automatic numbering continues from highest number used so far.
* OrderedDict implemetation for python < 2.7 taken from
  http://code.activestate.com/recipes/576693/