Add option to clusterSingleMarkers

src/MarkerClusterGroup.js

@@ -1,4 +1,3 @@
-
 /*
  * L.MarkerClusterGroup extends L.FeatureGroup by clustering the markers contained within
  */
@@ -8,6 +7,7 @@ L.MarkerClusterGroup = L.FeatureGroup.extend({
 	options: {
 		maxClusterRadius: 80, //A cluster will cover at most this many pixels from its center
 		iconCreateFunction: null,
+		clusterSingleMarkers: false,
 
 		spiderfyOnMaxZoom: true,
 		showCoverageOnHover: true,