Gateway performance optimizations and various resolved issues

Improvements

• Performance related optimizations.

Bug fixes

• Devices would show online when there was no driver communication.

• HydrogenManager would not always recover after a crash.

• Service could crash when deleting and readding a Certified Driver.

• Cgroup configuration now persists after a reboot.

• After editing attributes of a Certified Driver the state did not always change accordingly.

• Removed erroneous error messages from the log.

• Removed check for subscription-manager on non-RedHat Linux installations.

• Upgrading from VC-4 to XiO Cloud Gateway would still reference VC-4 instead of XiO Cloud Gateway.

Open issues

• Stopping a program with a number of SCIP devices connected could lead to a reboot of the control system.