An action set is responsible for the creation of actions.
The end user may add these actions to a workbench page menu and tool bar
if they are deemed useful to the particular task at hand.
[Issue: This interface is not exposed in API, but time may
demonstrate that it should be.
A named set of actions which is defined as an extension to the workbench
via the standard workbench actions extension point
("org.eclipse.ui.workbenchActions").