title: leafletjs marker bindpopup() with options
body: <p>The leaflet documention shows you can add a popup to a marker with</p>
  
  <pre><code>marker.bindPopup("&lt;b&gt;Hello world!&lt;/b&gt;&lt;br&gt;I am a popup.").openPopup();
  </code></pre>
  
  <p>or create a standalone popup with</p>
  
  <pre><code>var popup = L.popup()
      .setLatLng([51.5, -0.09])
      .setContent("I am a standalone popup.")
      .openOn(map);
  </code></pre>
  
  <p>Is there no way to set popup options and bind it to a marker? I want to be able to set my own maxwidth for popups and have them open/close when you click a marker.</p>