* 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.
