Change to OpenLayers javascript map.

Biggest change was changing to OpenLayers and adjusting the functions. OpenLayers requires you to add the event listeners when defining the map. There were more event listeners available so I was able to do the label transparency on drag thing that I wanted.
The biggest problem changing to OpenLayers was the projection change. I'd been using LatLon pairs of coordinates in the 'EPSG:4326' projection whereas OpenLayers was using LonLat pairs in the 'EPSG:900913' projection.
I also changed the map tiles used by default and some other minor changes.