Text and formatting cleanup.
Make RIAK_HOST environmental variable details into an info bubble.
Reword paragraph so that it doesn't start with "Since Riak 2.0".
Remove security mention.
Make "Write it like Riak. Query it like Solr." stand out more.
Make list out of special YZ fields.
Make list out of common HTTP response values.
Decode range query parameter for clarity.
Merge pull request #863 from basho/hc-search-fixes

General cleanup of 2.0 Using Search section