Realtime plugins should use existing notice layout instead of replicating it

There are a number of bugs caused by the Realtime plugins' layout and rendering of notices into the web page not matching the behavior of StatusNet's native user interface:

* geolocation info is missing entirely
* relative timestamps are not localized
* "from " is not localized
* plugin-enhanced sources such as OStatus source link are not passed through (in RT you see only 'from ostatus' instead of 'from identi.ca' with a link to source)
* context link is wrong http://status.net/trac/ticket/2088

While it might be possible to individually patch a bunch of them up, it's probably more reliable to use the exact same rendering for both, and send notices down the realtime pipes as formatted HTML instead of just the JSON.