Merge branch 'release/0.17'
Make search description specs match actual cases

In the largest Alaveteli instance, WDTK, only a fraction of tracks use
filters and these specs represent those that have actually been used
commonly.
Remove unused variable
Use entire descriptions for searches rather than assembling.

Assembling from phrases makes the descriptions impossible to translate -
just give complete descriptions for the most common cases.
Remove old unused code.
Remove obsolete line.

Should have been removed in
https://github.com/mysociety/alaveteli/commit/b236d4f113187b0e5d87867fc6512e5486f9764f.
Make track factory name a bit more specific.
Add notices for subscribing something you're subscribed to.

These notices are full sentences, rather than being composed of phrases,
which should make them easier to translate.
Add notices for subscribing to something.

These notices are complete sentences, not composed on the fly, so should
be easier to translate.
Add notices for unsubscribing from things.

These are full sentences, not composed on the fly, so should be easier
to translate.
Move track descriptions to a helper.

We can access url generation methods more easily here.
Remove CGI.escape calls.

Escaping will happen automatically in Rails 3.
Reformat for line length.
Make public body update titles translatable.

This way the translators can control the order of elements in the
sentence.
Remove explicit escaping calls

Will be done automatically in Rails 3
Merge branch 'feature/1310-better-track-translation' into rails-3-develop

Conflicts:
    spec/factories.rb
Merge branch 'rails-3-develop' of ssh://git.mysociety.org/data/git/public/alaveteli into rails-3-develop