Support functions in L.Util.template

Look at hash function in Wikimapia      
     L.tileLayer('http://{s}{hash}.wikimapia.org/?x={x}&y={y}&zoom={z}&r=7071412&type=hybrid&lng=1', {
        hash: function (data) {
          return data.x % 4 + (data.y % 4) *4;
        }
        , subdomains : 'i'
        , maxZoom: 18
        , attribution: '<a href="http://wikimapia.org" target="_blank">Wikimapia.org</a>'
      }).addTo(map);

http://olegsmith.github.com/leaflet.wikimapia/