* Persist: support serpent, and use by default over dump (as we assume consistency > readability in Persist).
* Logger/Dbg: Use serpent instead of dump to dump tables (it's slightly more compact, honors __tostring, and will tag tables with their ref, which can come in handy when debugging).
* Dbg: Don't duplicate Logger's log function, just use it directly.
* Fontlist/ConfigDialog: Use serpent for the debug dump.
* Call `os.setlocale(C, "numeric")` on startup instead of peppering it around dump calls. It's process-wide, so it didn't make much sense.
* Trapper: Use LuaJIT's serde facilities instead of dump. They're more reliable in the face of funky input, much faster, and in this case, the data never makes it to human eyes, so a human-readable format didn't gain us anything.
* This removes support for the following deprecated constants: `DTAP_ZONE_FLIPPING`, `DTAP_ZONE_BOOKMARK`, `DCREREADER_CONFIG_DEFAULT_FONT_GAMMA`
* The "Advanced settings" panel now highlights modified values in bold (think about:config in Firefox ;)).
* LuaData: Isolate global table lookup shenanigans, and fix a few issues in unused-in-prod codepaths.
* CodeStyle: Require module locals for Lua/C modules, too.
* ScreenSaver: Actually garbage collect our widget on close (ScreenSaver itself is not an instantiated object).
* DateTimeWidget: Code cleanups to ensure child widgets can be GC'ed.
Since I never actually needed to look into that data ever until today, let's just get rid of the weird debug-specific behavior.
Instead, just add a dedicated "Developer options" entry that will dump it on demand (and it'll be sorted to boot, which makes it 500% more usable).
Plus, since yesterday's change, the cache format switch between debug or not miiiight actually be crashy, so re-trigger the migration ;p.
* Includes a couple of noteworthy base bumps:
https://github.com/koreader/koreader-base/pull/1516 (update to sdcv 0.5.4 + fixes pending upstream)
https://github.com/koreader/koreader-base/pull/1517 (fix ffiUtil.orderedPairs with keys of mixed types)
* 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)
Cache's state tracking
Re #7510
Legacy cache has to be deleted in Cache,
*before* the first getDiskCache call.
Reword the "Clear caches" Dev menu entry & callback:
We now have an actual "Restart" action (on most, if not all, platforms).
And we clear the whole cache folder, which may host other things (e.g.,
fontlist)
