Add mechanism of automatic collection of milestone ids

Now we have some reports where user can click on number of bugs and he will be redirected to a certain launchpad page. The most part of such reports have a sorting by milestones, so after redirection to the launchpad user will see bugs targeted to a special milestone.

There is a problem in launchpad - it uses milestone id in urls instead of its names and there isn't any 'simple' calls which allow to get milestone id. So now we collect ids manually and keep them in a file.

The point is to reduce manual work and find the way to get milestone ids directly.