Rudimentary image loader.

This will just load the full image into memory. This is clearly
sub-optimal. There are a few cases that we need to consider:

* User zooms out the map a lot and we have to render it all:
  there's no helping it, we have to show it all.

* User doesn't zoom out (much) and we only have to show small pieces:
  perhaps we can chunk the map into multiple small fragments and then
  stitch the ones user is looking at. We might have a problem with the
  stitching taking too much time (stitching and loading is expensive) as
  the user flies around the map or zooms.
Print all Xlint warnings
Encapsulate map in something we can manipulate
Show placeholder image when out of bounds.
Centering on arbitrary geo-locations
Pair type

th-thanks Java
Skeleton of Node class