Added marker at coordinates in the url

Addresses issue #782

overviewer_core/data/js_src/overviewer.js

@@ -41,7 +41,12 @@ overviewer.collections = {
         /**
          * holds a reference to the spawn marker. 
          */
-        'spawnMarker': null
+        'spawnMarker': null,
+	
+	/**
+	 * if a user visits a specific URL, this marker will point to the coordinates in the hash
+	 */
+        'locationMarker': null
     };
 
 overviewer.classes = {
@@ -102,4 +107,4 @@ overviewer.gmap = {
                 return(urlBase + url);
             };
         }
-};
+};