Bug 113239 new compiler option 'fatalOptionalError'
* COMPILER / Treating Optional Error as Fatal * When enabled, optional errors (i.e. optional problems which severity is set to "error") will be treated as standard * compiler errors, yielding problem methods/types preventing from running offending code until the issue got resolved. * When disabled, optional errors are only considered as warnings, still carrying an error indication to make them more * severe. Note that by default, errors are fatal, whether they are optional or not. * - option id: "org.eclipse.jdt.core.compiler.problem.fatalOptionalError" * - possible values: { "enabled", "disabled" } * - default: "enabled" </pre>
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/OptionsConfigurationBlock.java
return fTextModifyListener;
	}		
	
	protected void controlChanged(Widget widget) {
		ControlData data= (ControlData) widget.getData();
		String newValue= null;
		if (widget instanceof Button) {
			newValue= data.getValue(((Button)widget).getSelection());			
		} else if (widget instanceof Combo) {
			newValue= data.getValue(((Combo)widget).getSelectionIndex());
		} else {
			return;
		}
		String oldValue= setValue(data.getKey(), newValue);
		validateSettings(data.getKey(), oldValue, newValue);
	}
	
	protected void textChanged(Text textControl) {
		Key key= (Key) textControl.getData();
		String number= textControl.getText();
		String oldValue= setValue(key, number);
		validateSettings(key, oldValue, number);
	}	
	protected boolean checkValue(Key key, String value) {
		return value.equals(getValue(key));
	}
	
	protected String getValue(Key key) {
		if (fDisabledProjectSettings != null) {
			return (String) fDisabledProjectSettings.get(key);