Bug 166015 Refactor designer actions to eclipse command framework
Eclipse command framework provide a more explicit way to manage UI actions contributions, we can take it's advantage to make our actions code more clean and maintainable.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/schematic/actions/EditGroupAction.java
{
	private static final String STACK_MSG_EDIT_GROUP = Messages.getString( "EditGroupAction.stackMsg.editGroup" ); 
	public static final String ID = "org.eclipse.birt.report.designer.internal.ui.editors.schematic.actions.EditGroupAction"; 
	private GroupHandle handle;
	/**
	 * @param part