Update guide/reference/query-dsl/query-string-query.textile

Important fuzzy option was missing from documentation

https://groups.google.com/forum/?fromgroups=#!topic/elasticsearch/Sj-9FpELhho
Update guide/reference/mapping/index.textile

Clarify the introductory sentence about mapping types.
Merge branch 'master' of https://github.com/elasticsearch/elasticsearch.github.com
Add release date for each download. Fix #367