Stateless ncwms get filters as json

 * Stateless `getFiltersAsJSON controller for ncwms
 * Stateless `getStylesAsJSON controller for ncwms
 * Client parsing is now much dumber
 * Date assembly is done in server side (grails)
 * Fix NcWMS GFI

This API is still work in progress, but enables us to see where we actually want to get to.
agreed