add tweaks of data retrieval zoom level, to make better use of the cache and be friendlier to the API in some cases

also, default-intel-detail and show-more-portals plugins fixed - the logic has been moved into IITC core, with the plugins just setting flags to change behaviour

code/utils_misc.js

@@ -282,6 +282,7 @@ window.androidPermalink = function() {
 
 window.getMinPortalLevel = function() {
   var z = map.getZoom();
+  z = getDataZoomForMapZoom(z);
   return getMapZoomTileParameters(z).level;
 }