- Add --media-root option (was half-supported already, but not accepted
on the command line).
- Don't test for Colosseum and XD graphics, since we have none.
- Acknowledge *-beta sprites.
All accessors now take a `root` arg, the root of the media tree.
Alternatively `root` can be a custom MediaFile subclass, which should allow
neat tricks like:
- Checking some kind of manifest to prevent stat() calls
- Custom properties of the file objects (e.g. for HTML <img> tags)
- Downloading the media on demand
Tests assume media is at pokedex/data/media, skip otherwise.
A few tests of the accessors, along with a very dumb, long-running script
to ensure everything is in its proper place, and there's nothing but the
proper things.
For now it still finds some beta form cruft for Burmy, Pichu and Cherrim.
