Routes with iso language code detection.

After reading <a
href="https://github.com/mikecao/flight/issues/39">about multilingual
routing with Flight</a> i decided to that and found out i had to map
every possible segement in my URLs with a (/[0-9a-z]+) to have the
language route drop in on any URL.

Added Controller_Admin::user() just to have another place to route to
as an example.