This is done by/for kosync plugin at each opening, because
the docsettings was re-opened and saved for this, but later
overwritten by the current koreader docsettings - so it was
redone each time. This correctly adds this partial_md5_checksum
to the current koreader docsettings, which will be saved on
document closing - so it will not be redone next time.
Note: this partial_md5_checksum is not (yet) used by anything.
1. Android.getScreenBrightness() is used in frontend/device/android/powerd.lua to retrieve the frontlight intensity.
2. kosync.koplugin won't save settings for whisper sync.
3. batterstat.koplugin won't work correctly if several on* events are fired.
MenuSorter: forgot to add plugin style change
MenuSorter: worked out the final quirks
* Menu always compressed into tables without missing indexes for ipairs compatibility
* Orphans attached
* Separators no longer count as items
1. It turns out that `device_id` is not defined in unit test environment
which makes the `assert(self.kosync_device_id)` fail and somehow makes `luajit` segmentation fault.
2. In the device spec, stubbing `io.open` will make subsquent `require`
all return boolean value and segmentation fault `luajit`.
This patch is a minimum viable change that makes CI work on both my
local box and Travis.
The 'KOSync' plugin will synchronize furthest reading progress
across different koreader devices after users registering their
devices.
The synchronizing service is open-sourced as the project
[koreader/koreader-sync-server](https://github.com/koreader/koreader-sync-server).
