Parse column headers to get location

• split code for getting the date form two different sources
• use os-release instead of lsb-release to get distribution id and codename

Keep the release date cached in the backend

• pointer syntax
• Require Qt 5.7
• set forwarded channels on the processes

I added a paragraph in the message box because, apparently, KMessageBox only wraps rich text when it it wider than 50% of the screen, which looks terrible on a wide screen.

• Open Muon (in Ubuntu)
• Look at the description of a supported package, e.g. accountsservice, acct, acl.
• The last line in the description says:

Canonical provides critical updates for acct until Donnerstag, 27. April 2023.

This patch brings back the date, which was missing.

This might look hacky, skipping two lines, but the alternative would be:

     // read the relase file
-    FileFd fd(releaseFile.toStdString(), FileFd::ReadOnly);
+    // This is what apt-pkg does in debReleaseIndex::Load(), but we are
+    // interested only in the Date field here.
+    FileFd fd;
+    if (!OpenMaybeClearSignedFile(releaseFile.toStdString(), fd)) {
+        return QDateTime();
+    }
     pkgTagFile tag(&fd);

• update with new function in QApt::Package

@sitter as for your comment on D13419, this patch adds the convenience function you mention.

drop categories

I also modified the template in the wiki page with the suggested changes. I hope that's fine.
https://community.kde.org/Guidelines_and_HOWTOs/AppStream

apply suggested changes

apply suggested fixes

remove comment left over

Git tells that the check was introduced in e70a781e (2010-09-25)
"Also check to see if the dpkg status file is newer than the xapian index, so that we can catch new packages installed directly via dpkg"

On my system (Ubuntu 17.10 artful) the apt package ships with /etc/apt/apt.conf.d/01-vendor-ubuntu which contains

Acquire::Changelogs::AlwaysOnline "true";

• Filter out URIs which are not http or https

Works here too on Qt 5.9.1. The patch was applied by Arcanist. Even worse: I was running the wrong executable. Feeling bad.

Testing with QT_SCALE_FACTOR=2 still shows pixelated text to me, but if it works on a real screen I'm fine with the changes. Thanks!