Keystone 1.2.13

Client fix. Replace the previous z-keystone jar in mods; the server can keep 1.2.9 or later.

Far copies with wrong textures after the texture set changed. Afterimage's far copies and its disk cache store block
geometry with texture coordinates in the block texture atlas. When the set of textures changes (a mod or resource pack
added or removed, or new item icons such as the ones 1.2.12 adds for Immersive Vehicles packs), most textures move to
other places in the atlas, and copies made before show other textures: roads drawn as grass, walls as leaves.

Afterimage now takes a fingerprint of the atlas layout after every texture load. The disk cache records the fingerprint
it was written with; if the layout differs at start-up, the old cache is moved to afterimage/cache-stale-<time> and
deleted in the background, and the far zone fills again as you play. A resource reload that changes the layout also
drops the copies in video memory. The log shows disk: cache discarded, it was made with another block texture layout
when that happens.

The first start with 1.2.13 discards the existing cache once, because it has no fingerprint yet.

Afterimage 0.5.9.