disable the country and year dropdowns

so people don't think they will work
Wire in the select boxes

On a select change we now recall the code to generate routes from csv
data and redraw the map.  Next step is to use the filters when
generating the routes.

Also put code in to distinguish between single and multiselects (but we
still need to make the UI support multiselect)
category filters selection now changes paths shown on map

Including allowing reset by choosing "any" value

Still need to properly support multiple selection in selection boxes
Allow filtering by year range