This changes the numeric format of many values printed to the UI to
reflect the correct numeric format of the selected locale:
- dot or comma as decimal separator
- comma or dot as thousands separator
In the Qt domain the `L` flag is used case specific mostly
in qthelper.cpp.
Then the helper functions get_xxx_string() are used more consistently.
Signed-off-by: Stefan Fuchs <sfuchs@gmx.de>
aacc688670