Fix moveCursor, fix all ids

Two fixes:
  - Fetching _next / _prev cursors didn't work for subdirs; that is, the _next/_prev cursor URL is relative to the location of the faceted search api; if it is located at http://foo.com/, fetching _next/_prev will be fine, but if it is located at http://foo.com/bar/, it will attempt to retrieve http://foo.com/search/, which will fail. This fix prepends the searchPath to _next/_prev URLs.

 - Fetches the complete list of all result IDs for inclusion in the responseModel. Not 100% sure this should be done every time. Gijs, what do you think?