updating OpenLayers imports in arcrest_example template

(release of OL3 seems to coincide with removal of OL dev stuff from
github - OL2 example, etc...)
adding TouchNavigation and PinchZoom controls

I had thought these were already included by default, but I witnessed
pinch controls not working on iPhone5 today…after receiving reports of
touch controls not working on OFR with Microsoft Surface Tablets
fixing SimpleLayerSwitcher references

so that the references refer to the class rather than the id, after
seeing the id change from SimpleLayerSwitcher_28 to
SimpleLayerSwitcher_30