Removed nav from #map page except back button

index.html - Removed the navigation from #map page, except back button
which should fit up in the header now.

mapstyles.css - Landscape code no longer needed. Map can just be
centered on the page since there's no nav on right anymore.

map.js - Calculate the height of the map by just setting the #map-canvas
height to the screen height minus height of header minus 25 pixels.