add highlighting

no styling yet, but search highlights are now being passed through the ajax call.
I changed the json format for elasticsearch to make it easier to search over.

Instead of:
{countries: [{name: "..."}, {name: "..."}]}

it now looks like: 
{countries_name: ["...", "...", "..."]}

Can we make the new as_json method what I have right now for as_indexed_json?