Multiple updates

Hi Wim,

Happy new year.

Here is a pull request with the following updates I did:

- Ranking support has been updated to include result in the XMPP bots and some tools added to view current rules for ranking.

- An update to avoid fetching unchanged files from MITRE. (Unclean but it works)

- Added a full-text indexer to overcome the limitation of the MongoDB search. The new full-text indexing query is constant time to get the CVE-ID and then you can fetch also in constant time from MongoDB the specified CVE.

Other pull requests will follow in the next days for the Atom/RSS support.

Enjoy and have fun.