Bug 316298 [Compatibility] Support o.e.ui.menus visibleWhen
We need support in MCoreExpression for entire expressions created by the WorkbenchMenuService. They don't often use ReferenceExpressions to core expression definitions. PW
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/workbench/UIEvents.java
public static final String TOPIC = UITopicBase + "/ui/UIElement"; 
		public static final String CONTAINERDATA = "containerData"; 
		public static final String CURSHAREDREF = "curSharedRef"; 
		public static final String ONTOP = "onTop"; 
		public static final String PARENT = "parent"; 
		public static final String RENDERER = "renderer"; 
		public static final String TOBERENDERED = "toBeRendered"; 
		public static final String VISIBLE = "visible"; 
		public static final String VISIBLEWHEN = "visibleWhen"; 
		public static final String WIDGET = "widget"; 
	}
	public static interface UILabel {
		public static final String TOPIC = UITopicBase + "/ui/UILabel"; 
		public static final String ICONURI = "iconURI"; 
		public static final String LABEL = "label"; 
		public static final String TOOLTIP = "tooltip"; 
	}
	public static interface HandledItem {
		public static final String TOPIC = UITopicBase + "/menu/HandledItem"; 
		public static final String COMMAND = "command"; 
		public static final String PARAMETERS = "parameters"; 
		public static final String WBCOMMAND = "wbCommand"; 
	}
	public static interface Item {
		public static final String TOPIC = UITopicBase + "/menu/Item"; 
		public static final String ENABLED = "enabled"; 
		public static final String SELECTED = "selected"; 
		public static final String TYPE = "type"; 
	}
	public static interface Menu {