Better content discovery through cross-linking

[sebbacon]

We should expose tags to end users (#2302), consider allowing them to add tags themselves, and use them to cross-reference possibly related requests.

Tags can also be automatically generated (for english, at least) - see https://github.com/sebbacon/alaveteli/issues/19

We can also consider cross-linking authority names where they appear in the text body, and could perhaps also geotag entries based on OpenCalais city / county data.

[sebbacon]

See also issue #67

[sebbacon]

Add interface for editing tags on your own requests so you can keep track of them more easily.
Lisa asked for this - is definitely only whole requests needed. Tony says
anyone should be able to edit the tags, but requester should have last say (so
can prevent a tag being added that they removed).

[crowbot]

We have interest from GONG in Croatia in having a pre coded set of tags attached to the Alaveteli instance that can be used to filter requests in search.

[HelenWDTK]

This issue has been automatically closed due to a lack of discussion or resolution for over 12 months.
Should we decide to revisit this issue in the future, it can be reopened.