Bug 318497 Tool items are always enabled
Because we're not calling the underlying HandledItem's canExecute method.
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/ToolItemRenderer.java
if (modelParms != null && !modelParms.isEmpty()) {
			parameters = new HashMap<String, Object>();
			for (MParameter mParm : modelParms) {
				parameters.put(mParm.getName(), mParm.getValue());
			}
		}
		ParameterizedCommand cmd = cmdService.createCommand(item.getCommand()
				.getElementId(), parameters);
		item.setWbCommand(cmd);
		return cmd;
	}
	private void setItemText(MToolItem model, ToolItem item) {
		String text = model.getLabel();
		if (model instanceof MHandledItem) {
			MHandledItem handledItem = (MHandledItem) model;
			IEclipseContext context = getContext(model);
			EBindingService bs = (EBindingService) context
					.get(EBindingService.class.getName());
			ParameterizedCommand cmd = handledItem.getWbCommand();
			if (cmd == null) {
				cmd = generateParameterizedCommand(handledItem, context);
			}
			TriggerSequence sequence = bs.getBestSequenceFor(handledItem
					.getWbCommand());
			if (sequence != null) {
				text = text + '\t' + sequence.format();
			}
			item.setText(text);
		} else {
			if (text == null) {