Tweak last completed deploy to only consider the last 90 days

The last completed deploy query currently considers all history which means that we still list stages that haven't existed for ages.
Display build information on deploy page

When selecting a build, try and display more information about it on the
right hand side of the page. This makes calls back to Riff-Raff which
in turn makes calls to TeamCity to get updated information about valid
builds.
Change plurality of method call to be consistent and sane
Change model to pull down tags only rather than litter the mutable tag concept in with the immutable build data.
Merge pull request #196 from guardian/sh-build-info

Improve information on deployment page