Bug 63840 warning on unused labels
we have warnings for all sorts of unused things. one for unused labels would be good too.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/ProblemSeveritiesConfigurationBlock.java
protected Control createContents(Composite parent) {
		fPixelConverter= new PixelConverter(parent);
		setShell(parent.getShell());
		
		Composite mainComp= new Composite(parent, SWT.NONE);
		mainComp.setFont(parent.getFont());
		GridLayout layout= new GridLayout();
		layout.marginHeight= 0;
		layout.marginWidth= 0;
		mainComp.setLayout(layout);
		
		Composite commonComposite= createStyleTabContent(mainComp);
		GridData gridData= new GridData(GridData.FILL, GridData.FILL, true, true);
		gridData.heightHint= fPixelConverter.convertHeightInCharsToPixels(20);
		commonComposite.setLayoutData(gridData);
		
		validateSettings(null, null, null);
	
		return mainComp;
	}
	
	private Composite createStyleTabContent(Composite folder) {
		String[] errorWarningIgnore= new String[] { ERROR, WARNING, IGNORE };
		
		String[] errorWarningIgnoreLabels= new String[] {
			PreferencesMessages.ProblemSeveritiesConfigurationBlock_error,  
			PreferencesMessages.ProblemSeveritiesConfigurationBlock_warning, 
			PreferencesMessages.ProblemSeveritiesConfigurationBlock_ignore
		};