* Android: Make sure sdcv can find the STL
* DocCache: Be less greedy when serializing to disk, and only do that for the *current* document ;).
* CanvasContext: Explicitly document API quirks.
* Fontlist: Switch the on-disk Persist format to zstd (it's ever so slightly faster).
* Bump base for https://github.com/koreader/koreader-base/pull/1515 (fix#9506)