Move code to send signals and set priority of processes to a dedicated object
This pulls the code out of KSysGuardProcessList and introduces it in a
new class called ProcessController. This should help make that code more
reusable and allow it to eventually be exposed to QML.
Start ksysguard, try to send signals to processes and set priorities, including
root-owned processes. Everything should still work.
Reviewers: Plasma, davidedmundson
Reviewed By: Plasma, davidedmundson
Subscribers: davidedmundson, plasma-devel
Differential Revision: https://phabricator.kde.org/D23566