Bug 6718 Error ticks on non-Java resources
This is a VAME request. They would like to show error ticks on manifest files.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/JavaElementLabelProvider.java
/*
	 * Dispose the cached images for JarEntry files 
	 */
	private void disposeJarEntryImages() {
		Iterator each= fJarImageMap.values().iterator();
		while (each.hasNext()) {
			Image image= (Image)each.next();
			image.dispose();
		}
		fJarImageMap.clear();
	}
	
	/*
	 * Gets and caches an image for a JarEntryFile.
	 * The image for a JarEntryFile is retrieved from the EditorRegistry.
	 */ 
	private Image getImageForJarEntry(IStorage element) {
		String extension= element.getFullPath().getFileExtension();
		Image image= (Image)fJarImageMap.get(extension);
		if (image != null) 
			return image;
		IEditorRegistry registry= PlatformUI.getWorkbench().getEditorRegistry();
		ImageDescriptor desc= registry.getImageDescriptor(element.getName());
		image= desc.createImage();
		fJarImageMap.put(extension, image);
		return image;
	}
}