title: Leaflet custom projection
body: <p>I'm starting with Leaflet and I'm trying make a example with custom projection (EPSG:23030) to show a layer from WMS service. If I do not know the resolutions, how can I make it? I have this code, using the plugin Proj4Leaflet, but it doesn't work:</p>
  
  <pre><code>var crs23030 = new L.Proj.CRS('EPSG:23030','+proj=utm +zone=30 +ellps=intl +units=m +no_defs');
  var map = new L.Map('map', {
      crs: crs23030
  });
  
  L.tileLayer.wms('http://www.juntadeandalucia.es/servicios/mapas/callejero/wms', {
      layers: 'CallejeroCompleto',
      format: 'image/jpeg',
      maxZoom: 13,
      minZoom: 0          
  }).addTo(map);
  
  map.setView(new L.LatLng(37.24344,-4.23522), 7);
  </code></pre>