javascript cleanup

* remove trailing whitespace (I'm a nazi for that)
* create top level application namespace: window.OJ
* create first class object OJ.Maps
   - holds logic for instantiating map
   - creates the legend
   - holds icon urls
   - keeps an accessible reference to google.maps.Map instance
   - keeps an accessible reference to google.maps.Geocoder instance
* move style logic for legend to CSS
* use jQuery to construct legend DOM, convenient