Support dumping/rendering a selection of regions

[samszotkowski]

This lets us specify in version.txt if we want to dump/render any particular regions (e.g. only ones that have changed since previous cache). stitch.py still needs access to all of the base tiles whether those particular regions are selected or not, so it can render plane 0 without any stitch lines, and for the zoomed out images, of which a selected region might only be a tiny part.

Note that it doesn't just render the selected regions, but also all adjacent regions in case map icons have been altered that would cross the boundary of the selected regions into adjacent ones.

[allenkinzalow]

It looks like it is rendering the map icons in other regions, but not the other regions.

[samszotkowski]

Interesting, did you have anything in your base tiles folder before running or did you start from scratch w/ a selection?

[samszotkowski]

The idea of selections was that you have the previous tiles already rendered and you just need to add or replace some, so using a selection assumes the base tiles directory is already full. It will use the existing base tiles to generate those zoomed out images, but if they don't exist then you'll get garbage... I think that's what's happening here