Lat lon zoom in url

* Autocomplete based on zoom levels (upto zoom=7, uses precision=1, zoom 7-9 uses precision 2 and anything above zoom 9 uses precision 3) NOTE: we only have 3 precision levels to play with right now 
* Adds lat/lng/zoom in the url
* Remembers where you were using a cookie
* Falls back to geolocating you if you are visiting the demo page for the first time