disable 'timestampMs' map data requests. either i've misunderstood what their code is doing, or it's an incomplete feature in the stock site.

extensive testing has never found an instance where it reduced response size from the server

code/map_data_request.js

@@ -252,6 +252,9 @@ window.MapDataRequest.prototype.refresh = function() {
           lngEast
         );
 
+/* After some testing, this doesn't seem to actually work. The server returns the same data with and without the parameter
+ * Also, closer study of the stock site code shows the parameter isn't actually set anywhere.
+ * so, disabling for now...
         // however, the server does support delta requests - only returning the entities changed since a particular timestamp
         // retrieve the stale cache entry and use it, if possible
         var stale = (this.cache && this.cache.get(tile_id));
@@ -275,6 +278,7 @@ console.log('stale tile '+tile_id+': newest mtime '+lastTimestamp+(lastTimestamp
             boundsParams.timestampMs = lastTimestamp;
           }
         }
+*/
 
         this.tileBounds[tile_id] = boundsParams;
         this.requestedTileCount += 1;
@@ -504,6 +508,7 @@ window.MapDataRequest.prototype.handleResponse = function (data, tiles, success)
 
         var stale = this.requestedTiles[id].staleData;
         if (stale) {
+//NOTE: currently this code path won't be used, as we never set the staleData to anything other than 'undefined'
           // we have stale data. therefore, a delta request was made for this tile. we need to merge the results with
           // the existing stale data before proceeding