* Wireless: Optimize memory usage in StreamMessageQueue (use an array of string ropes, that we only concatenate once). Allowed to relax the throttling, making transfers that much faster.
* Persist: Add a "zstd" codec, that uses the "luajit" codec, but compressed via zstd. Since both of those are very fast, it pretty much trounces everything in terms of speed and size ;).
* Persist: Implemented a "writes_to_file" framework, much like the existing "reads_from_file" one. And use it in the zstd codec to avoid useless temporary string interning.
* Metadata: Switch to the zstd codec.
* CalibreMetadata: Get rid of the now useless NULL-hunt: here, this was basically looking for `rapidjson.null` to replace them with... `rapidjson.null` :?. IIRC, that's a remnant of a quirk of the previous JSON parser (possibly even the previous, *previous* JSON parser ^^).
* CalibreSearch: Update the actually relevant NULL-hunt to make it explicit: replace JSON NULLs with Lua nils, instead of relying on an implementation detail of Lua-RapidJSON, because that detail just changed data type ;).
* UIManager: Make sure tasks scheduled during the final ZMQ callback are honored. e.g., the Calibre "Disconnect" handler. This happened to mostly work purely by chance before the event loop rework.
* Calibre: Restore a proper receiveCallback handler after receiving a book, in order not to break the "Disconnect" handler's state (and, well, get a working Disconnect handler, period ^^).
* Calibre: Unbreak metadata cache when it's initialized by a search (regression since #7159).
* Calibre: Handle UTC <-> local time conversions when checking the cache's timestamp against the Calibre metadata timestamp.
* Bump base (Unbreak CRe on Android, update RapidJSON)
* LuaSettings/DocSettings: Updated readSetting API to allow proper initialization to default.
Use it to initialize tables, e.g., fixing corner-cases in readerFooter that could prevent settings from being saved.
(Fixes an issue reported on Gitter).
* LuaSettings/DocSettings: Add simpler API than the the flip* ones to toggle boolean settings.
* Update LuaSettings/DocSettigns usage throughout the codebase to use the dedicated boolean methods wher appropriate, and clean up some of the more mind-bending uses.
* FileChooser: Implement an extended default exclusion list (fix#2360)
* ScreenSaver: Refactor to avoid the pile of kludges this was threatening to become. Code should be easier to follow and use, and fallbacks now behave as expected (fix#4418).
* Menu/KeyValuePage/ReaderGoTo: Unify the dialogs. (Generally, "Enter page number" as title, and "Go to page" as OK button).
* Allow *tapping* on pagination buttons, too. Added spacers around the text to accommodate for that.
* Disable input handlers when <= 1 pages, while still printing the label in black.
* Always display both the label and the chevrons, even on single page content. (Menu being an exception, because it can handle showing no content at all, in which case we hide the chevrons).
* KVP: Tweak the pagination buttons layout in order to have consistent centering, regardless of whether the return arrow is enabled or not. (Also, match Menu's layout, more or less).
* Menu: Minor layout tweaks to follow the KVP tweaks above. Fixes, among possibly other things, buttons in (non-FM) "List" menus overlapping the final entry (e.g., OPDS), and popout menus with a border being misaligned (e.g., Calibre, Find a file).
* CalendarView: Minor layout tweaks to follow the KVP tweaks. Ensures the pagination buttons are laid out in the same way as everywhere else (they used to be a wee bit higher).
* Revamped most actions that require an internet connection to a new/fixed backend that allows forwarding the initial action and running it automatically once connected. (i.e., it'll allow you to set "Action when Wi-Fi is off" to "turn_on", and whatch stuff connect and do what you wanted automatically without having to re-click anywhere instead of showing you a Wi-Fi prompt and then not doing anything without any other feedback).
* Speaking of, fixed the "turn_on" beforeWifi action to, well, actually work. It's no longer marked as experimental.
* Consistently use "Wi-Fi" everywhere.
* On Kobo/Cervantes/Sony, implemented a "Kill Wi-Fi connection when inactive" system that will automatically disconnect from Wi-Fi after sustained *network* inactivity (i.e., you can keep reading, it'll eventually turn off on its own). This should be smart and flexible enough not to murder Wi-Fi while you need it, while still not keeping it uselessly on and murdering your battery.
(i.e., enable that + turn Wi-Fi on when off and enjoy never having to bother about Wi-Fi ever again).
* Made sending `NetworkConnected` / `NetworkDisconnected` events consistent (they were only being sent... sometimes, which made relying on 'em somewhat problematic).
* restoreWifiAsync is now only run when really needed (i.e., we no longer stomp on an existing working connection just for the hell of it).
* We no longer attempt to kill a bogus non-existent Wi-Fi connection when going to suspend, we only do it when it's actually needed.
* Every method of enabling Wi-Fi will now properly tear down Wi-Fi on failure, instead of leaving it in an undefined state.
* Fixed an issue in the fancy crash screen on Kobo/reMarkable that could sometime lead to the log excerpt being missing.
* Worked-around a number of sneaky issues related to low-level Wi-Fi/DHCP/DNS handling on Kobo (see the lengthy comments [below](https://github.com/koreader/koreader/pull/6424#issuecomment-663881059) for details). Fix#6421
Incidentally, this should also fix the inconsistencies experienced re: Wi-Fi behavior in Nickel when toggling between KOReader and Nickel (use NM/KFMon, and run a current FW for best results).
* For developers, this involves various cleanups around NetworkMgr and NetworkListener. Documentation is in-line, above the concerned functions.
joins calibre metadata search and calibre wireless connections into a single plugin
search metadata changes:
- search directly into calibre metadata files.
- search can be performed on more than one library (configurable from a menu)
- device scans now find all calibre libraries under a given root
- search options can be configured from a menu. (case sensitive, find by title, author and path)
- removed legacy global variables.
- *option* to search from the reader
- *option* to generate a cache of books for faster searches.
calibre wireless connection changes:
- keep track of books in a library (includes prunning books from calibre metadata if the file was deleted locally)
- remove files on device from calibre
- support password protected connections
- FM integration: if we're in the inbox dir it will be updated each time a book is added or deleted.
- disconnect when requested by calibre, available on newer calibre versions (+4.17)
- remove unused opcodes.
- better report of client name, version and device id
- free disk space checks for all calibre versions
- bump supported extensions to match what KOReader can handle. Users can override this with their own list of extensions (or from calibre, by configuring the wireless device).
