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/JavaBuildConfigurationBlock.java
String message;
		if (workspaceSettings) {
			message= PreferencesMessages.JavaBuildConfigurationBlock_needsfullbuild_message; 
		} else {
			message= PreferencesMessages.JavaBuildConfigurationBlock_needsprojectbuild_message; 
		}
		return new String[] { title, message };
	}
	private IStatus validateMaxNumberProblems() {
		String number= getValue(PREF_PB_MAX_PER_UNIT);
		StatusInfo status= new StatusInfo();
		if (number.length() == 0) {
			status.setError(PreferencesMessages.JavaBuildConfigurationBlock_empty_input); 
		} else {
			try {
				int value= Integer.parseInt(number);
				if (value <= 0) {
					status.setError(Messages.format(PreferencesMessages.JavaBuildConfigurationBlock_invalid_input, number)); 
				}
			} catch (NumberFormatException e) {
				status.setError(Messages.format(PreferencesMessages.JavaBuildConfigurationBlock_invalid_input, number)); 
			}
		}
		return status;
	}
	private IStatus validateResourceFilters() {
		String text= getValue(PREF_RESOURCE_FILTER);
		
		IWorkspace workspace= ResourcesPlugin.getWorkspace();