capability plugin : RegexpFieldValidator inverse logic

    @Override
    public ValidationResult validate( final Map<String, String> properties )
    {
        if ( properties != null )
        {
            final String value = properties.get( key );
            if ( value != null && pattern.matcher( value ).matches() )
            {
                return new DefaultValidationResult().add( key, label + " does not match '" + pattern.pattern() + "'" );
            }
        }
        return ValidationResult.VALID;
    }