Resolve bugs related to COALESCE problems

* Make sure conditions are checked in both WHERE and COALESCE
  Checking the condition in the WHERE class is necessary for performance.
  Checking the condition in the COALESCE is necessary to prevent unrendered tags
  blocking rendering of tags further down in the COALESCE.
  See also the discussion [here](gravitystorm#1038 (comment)).

  This is an improvement of gravitystorm#1038.

  This resolves gravitystorm#985, resolves gravitystorm#1029, resolves gravitystorm#1336.

* Give amenity priority over shop.

  This resolves gravitystorm#963.

* Give tourism priority over amenity, shop, leisure, landuse, man_made, natural,
  and place.

  This resolves gravitystorm#1269, resolves first issue of gravitystorm#1232.