Uses KPluginLoader+KPluginMetadata instead.
Describes plugins in json instead of desktop files. These desktop files are
then embedded into the .so file. All the plugins will be in a kdeconnect/
directory, and those will be the ones to look for.
Note it doesn't drop the KService dependency as KIOCore is a KDE Connect
dependency as well.
REVIEW: 123042
Ported using KDELibs4Support, for a smaller delta, so we can keep
developing on master until we decide not to.
At the moment, it builds and installs but tests don't pass because
of a QCA2 initialization problem I didn't manage to debug yet.
CCMAIL: kdeconnect@kde.org
