* UIManager: Let the fb backend deal with Kaleido wfm promotion. This fixes a number of quirks that poisoned the refresh queue with spurious full-screen refreshes. See https://github.com/koreader/koreader-base/pull/1865 for more details.
* This also means we now disable Kaleido waveform modes when color rendering is disabled (remember to trash your thumbnail cache if you don't want to mix color w/ grayscale thumbnails, though).
* UIManager: Merge refreshes that share an edge, because that was driving me nuts (and would have most likely been merged by the kernel anyway). A perfect test-case is the FM, which trips two separate refreshes because of its title bar.
* ReaderFlipping: Use sensible dimensions, so that we only refresh the icon's region.
* ReaderBookmark: Only refresh the dogear instead of the whole page when toggling bookmarks.
* NetworkSetting: Make it a real boy, so it consistently refreshes properly on dismiss instead of relying on UIManager saving the day.
* Kobo: Aggressively prevent *both* suspend & standby while MTK devices are plugged-in, as both will horribly implode the kernel (we previously only prevent standby while charging).
* Kobo: Switch to 8bpp on B&W MTK devices (or when color rendering is disabled on Kaleido panels).
Basically:
* Use `extend` for class definitions
* Use `new` for object instantiations
That includes some minor code cleanups along the way:
* Updated `Widget`'s docs to make the semantics clearer.
* Removed `should_restrict_JIT` (it's been dead code since https://github.com/koreader/android-luajit-launcher/pull/283)
* Minor refactoring of LuaSettings/LuaData/LuaDefaults/DocSettings to behave (mostly, they are instantiated via `open` instead of `new`) like everything else and handle inheritance properly (i.e., DocSettings is now a proper LuaSettings subclass).
* Default to `WidgetContainer` instead of `InputContainer` for stuff that doesn't actually setup key/gesture events.
* Ditto for explicit `*Listener` only classes, make sure they're based on `EventListener` instead of something uselessly fancier.
* Unless absolutely necessary, do not store references in class objects, ever; only values. Instead, always store references in instances, to avoid both sneaky inheritance issues, and sneaky GC pinning of stale references.
* ReaderUI: Fix one such issue with its `active_widgets` array, with critical implications, as it essentially pinned *all* of ReaderUI's modules, including their reference to the `Document` instance (i.e., that was a big-ass leak).
* Terminal: Make sure the shell is killed on plugin teardown.
* InputText: Fix Home/End/Del physical keys to behave sensibly.
* InputContainer/WidgetContainer: If necessary, compute self.dimen at paintTo time (previously, only InputContainers did, which might have had something to do with random widgets unconcerned about input using it as a baseclass instead of WidgetContainer...).
* OverlapGroup: Compute self.dimen at *init* time, because for some reason it needs to do that, but do it directly in OverlapGroup instead of going through a weird WidgetContainer method that it was the sole user of.
* ReaderCropping: Under no circumstances should a Document instance member (here, self.bbox) risk being `nil`ed!
* Kobo: Minor code cleanups.
This commit standardizes the various todos around the code a bit in a manner recognized by LDoc.
Besides drawing more attention by being displayed in the developer docs, they're also extractable with LDoc on the command line:
```sh
ldoc --tags todo,fixme *.lua
```
However, whether that particular usage offers any advantage over other search tools is questionable at best.
* and some random beautification
