Bug 318930 Be lazy: Convert HandlerActivation from RunAndTrack to ContextFunction (pull instead of push)
bundles/org.eclipse.e4.core.commands/src/org/eclipse/e4/core/commands/internal/HandlerServiceImpl.java
final static String H_ID = "handler::"; 
	public final static String PARM_MAP = "parmMap::"; 
	final static String LOOKUP_HANDLER = "handler"; 
	public static Object lookUpHandler(IEclipseContext context, String commandId) {
		IEclipseContext current = context;
		IEclipseContext child = (IEclipseContext) current.getLocal(IContextConstants.ACTIVE_CHILD);
		while (child != null) {
			current = child;