Clean up streamer and base URI usage

Factor out a socket factory into a service and send the client ID only
before the first message. Configure the client ID and this service in a
new module, h.socket. Fix the base URI to end in a slash and to be the
root URL of the server.
Simplify visualsearch usage in app controller

Make a directive for visualsearch that eases integration by taking
care of digest cycles and providing declarative binding for events.

Remove the state tracking with inSearch and will_search and replace
it by reflect the search directly in the query string.