Boost Ministers, Organisations, and Topical Events

These things are more important than news stories, speeches, etc. within the Inside Government data model. This boosting gives them a relatively higher weight versus other things that match, because users should always be able to find:

- The G8 itself, versus a news article about the G8
- David Cameron versus an article about David Cameron visiting a hospital
- The Ministry of Defense versus an publication about HR within the MOD

In the future we should do some work to offer per-index boosting instead of doing it blanketly (given that the format names are quite generic, and there's no cross-platform data model).