Bug 17168 Packages view: Open in context menu for * imports
Test pass 1 - JUnit setup - open AboutDialog - select java.awt.event.* - open context menu observe: Open is in context menu, although it can't be applied.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/OpenAction.java
this(editor.getEditorSite());
		fEditor= editor;
		setText(ActionMessages.getString("OpenAction.declaration.label")); 
		setEnabled(SelectionConverter.canOperateOn(fEditor));
	}
	
	/* (non-Javadoc)
	 * Method declared on SelectionDispatchAction.
	 */
	protected void selectionChanged(ITextSelection selection) {
	}
	/* (non-Javadoc)
	 * Method declared on SelectionDispatchAction.
	 */
	protected void selectionChanged(IStructuredSelection selection) {
		setEnabled(checkEnabled(selection));
	}
	
	private boolean checkEnabled(IStructuredSelection selection) {
		if (selection.isEmpty())
			return false;
		for (Iterator iter= selection.iterator(); iter.hasNext();) {
			Object element= (Object)iter.next();
			if (element instanceof IImportDeclaration && !((IImportDeclaration)element).isOnDemand())
				continue;
			if (element instanceof ISourceReference)
				continue;
			if (element instanceof IResource)
				continue;
			if (element instanceof IStorage)