Initial embedded map

A version of the map that can be embedded to other websites within an iframe. The state of the embedded map can be defined with the url.

Some styling is still work in progress.

*Urls*
show a unit ``/#unit/123``
show a district ``/#unit/?division=helsinki/kaupunginosa:kallio``
show a district with a title bar filter ``/#unit/?division=helsinki/kaupunginosa:kallio&tb``
show multiple districts ``/#unit/?division=helsinki/kaupunginosa:kallio,helsinki/kaupunginosa:lauttasaari``
show a service ``/#unit/?service=25006``
show multiple services ``/#unit/?service=25006,25010``