-  http_404(+Options, +Request) is det
 - Reply using an "HTTP 404 not found" page. This handler is
intended as fallback handler for prefix handlers. Options
processed are:
- index(Location)
 - If there is no path-info, redirect the request to
Location using http_redirect/3.
 
- Errors
 - - 
http_reply(not_found(Path))