added icons that can change their image,

added image change while dragging markers,
increased (invisible) size of drag marker,
fixed issues with drag marker and highlight marker overlapping

WebContent/main.html

@@ -42,6 +42,7 @@ or see http://www.gnu.org/licenses/agpl.txt.
 <script src="L.Bugfixes.js" type="text/javascript"></script>
 <script src="L.DashedPolyline.js" type="text/javascript"></script>
 <script src="L.MouseMarker.js" type="text/javascript"></script>
+<script src="L.SwitchableIcon.js" type="text/javascript"></script>
 
 <script src="OSRM.base.js" type="text/javascript"></script>
 <script src="OSRM.config.js" type="text/javascript"></script>