Fix map bounds

Adjusted two things about the map:

1. It starts centered on the US. This seems legit.
2. It has a bounds set that will not allow people to pan across the international date-line. What happens is that if you pull the map as though you tried to pan across the dateline, you can, and you see the basemap repeated. However once you let go, the map will bounce back to the right view of the world.

This is to solve #119. @rwschwanke can you please notify anyone who needs to test this? Otherwise I'll merge on Dec 3rd.