Strings are prefilled by msgmerge with closely matching ones to reduce the amount of labor required by the translator. Often the string requires only minor adjustment, making the process faster, and when the string isn't a good match it's no big deal. However, these so-called fuzzy strings shouldn't be treated as if they were actually translated.
Fixes the effect seen in <https://github.com/koreader/koreader/issues/5806>.
References https://github.com/koreader/koreader/issues/5232
Given an entry in the PO file like the following:
```
msgctxt "systemstat"
msgid " Total"
msgstr "Totaal"
```
It can be addressed using:
```lua
local _ = require("gettext")
local C_ = _.pgettext
C_("systemstat", " Total")
```
This allows to distinguish between separate instances of the same string, for example "Pages" meaning "Number of pages" and "Pages" meaning "Display of pages".
Extraction of this code pattern is not yet implemented by nightswatcher. xgettext didn't yet support Lua back in 2013 when all this was first added to the program, but now it does. Therefore it might make the most sense to replace the current Python extraction script with xgettext itself.
By default it only understands gettext.pgettext(), but that can be addressed by passing some extra command line arguments, for example:
```
xgettext -l lua -c --keyword=C_:1c,2 *.lua
```
* use product as device model
* print android version (codename + number) + api at launch
* exit the application properly
* fix fullscreen switching (and disable it on newer android versions)
* gettext: lower log level for message: cannot open translation file
* android common settings refactor
