OMG UI!!

- Added a lovely Introduction to the page upon first visit. <3
- UI ELEMENTS! Buttons, Credits, Footnotes OH MY!
- Added Pinning: plop a pin down, and the hash tag changes. This means
linking straight to a tile!
- Added a button for zooming in and out, with proper footnote if the
zoom is not properly supported.
- Added button that allows the user to go back to the center of the map.
Exploration without getting lost!
- AND MOBILE SUPPORT! Dragging and tapping should now work on the iPad!
:D