Fixes#20776. At some point, the call to rebuild the sycoca database at startup
was removed, but it will not be rebuilt automatically because the timestamps in
the Nix store never change.
The desktop session variables need to be initialized before loading the
user environment scripts so that these scripts can exec programs that
rely on the session variables. For example, these variables must be set
when gpg-agent is started or pinentry-qt will not respect the user's
theme settings.
* Read the screen scale factor (for HiDPI displays) from KScreen
correctly.
* Disable automaticy scale factor detection in Qt applications.
* Force font DPI at startup, if requested.
* Allow kded to invoke kbuildsycoca5 automatically.
- Update from Plasma 5.7.0 to 5.7.1.
- Remove the version number from the directory storing the Plasma Nix
expressions. It is not necessary to version the Nix expressions now
that we keep only one version in Nixpkgs.
- Fix a bug in generate-kde-plasma.sh which prevented it from finding
its helper script.
- Automatically redirect the output of generate-kde-plasma.sh to make
the update script even easier to use.
