title: Start-Marker from geojson polyline
body: <p>i have a map with some walking- and bike-routes and popups with a few details an a pic. Now i want to set a marker on the first vertex of a geojson polyline, but i cant find out how. Btw. i´m new to leaflet/mapbox, and i put my map togehter from code snippets.<br>
  <a href="http://dl.dropboxusercontent.com/u/57482/much/index.html" rel="nofollow">Here is the map now:</a></p>
  
  <p>This is how i create the polylines now. I call them via layercontrol.</p>
  
  <pre><code>var mtb = L.geoJson(radjs, {
  filter: function (feature, layer) {
      if (feature.properties) {
          // If the property "underConstruction" exists and is true, return false (don't render features under construction)
          return feature.properties.typ === 'mtb';
      }
      return true;
  },
  style: {
      "color": '#6699cc',
      dashArray: '',
      "weight": 4,
      "opacity": 0.6
  },    onEachFeature: onEachFeature2}).addTo(rad);
  </code></pre>
  
  <p>Thank you for your help,
  Marc</p>