[WIP] Implement ES suggest API for Rocketbar suggestions (bug 915701)

https://bugzilla.mozilla.org/show_bug.cgi?id=915701

WIP. Unfortunately I'm not sure there a solution for filtering (all docs seem to suggest that's impossible), so I'm considering only filling up `name_suggest` for firefoxos devices since it's a Firefox OS specific API. As for region and buchets, this API will probably not filter on those since Firefox OS doesn't have our code to generate those parameters.