Revised North America Map, added lakes and rivers, some manual edits
around the northern coasts to preserve the jagged fjordness, added ~53
bots to the json, to fill in all the empty space (makes for a very fun
solo run, may need to reduce somewhat once the players get a chance to
try it).
Added 50 US state flags to the resources folder.
**Can now Nuke Santa.**
Also updated the map loader to now run on every single map (in the
`maps` array).
Also now maps are loaded concurrently (run every promise at the same
time and wait that they are all finished). As the functions are CPU
bound and not IO bound running concurrently doesn't change much right
now but it can if we use more promise in the function loadTerrainMap
then things will get faster.
APuddle210