Remove properties that are not used or not useful.
The "id" property is implemented by the desktop entry
X-GNOME-Settings-Panel value and the extension point implementation name.
The "display-name" property is not used because the Name value from the
desktop entry file is read instead.
The "active" property is no longer needed, since the objects are not kept
alive when the panel is inactive.
CcShell is an abstract class that represents an instance of a control
center shell. It provides access to some of the properties of the shell
that panels will need to read or change. When a panel is created it has an
instance of CcShell available that represents the current shell.
CcPanel is an abstract class used to implement panels for the shell. A
panel contains a collection of related settings that are displayed within
the shell window.
