Provide simple set-up for imported translations

As part of crowd-sourcing set-up for translations import, we need to make it easy. Ideally, automate it (i.e. scan branches and if we see translations in them, just set it up), but for now, let's make it dead easy.

First step would be to modify a LP project translations page to:

 1. recommend setting up a sourcepackage link to Ubuntu package if one doesn't exist (anyone can do this, depends on existing registry functionality)
 2. demand entering an upstream branch if one is not linked for the development_focus/translation_focus series (anyone can do this)
 3. "set up translations" step which does:
  * ensure translation_focus is set (default to development_focus)
  * set translation_focus series translations import to "both templates and translations"
  * set project translations policy to 'closed' (and make sure this does indeed close out translations to everybody)
  * does an initial translations import

We'd have to be careful with permissions since we want everybody to be able to set this up whenever a project is not officially using LP for that specific task. Changing this data will require better standing of a user.