Comprehensive HTTP Router

Here is a partial solution to Issue #202, at least for different HTTP methods.  There is no provision for websocket or SSE support here.  This is more or less a port of the excellent Vert.x RouteMatcher for RxNetty.  I do want to point out that I had to force queryParameters to be mutable on HttpRequest for this particular implementation.
True the `close()` call returns an `Observable` but thats the result of the `close()` invocation and does not indicate the result of `handle()`. I think we should not even call `close()` here, it should be up to the handler implementation (matching the uri) to call or not call close on the response.