private boolean isLegalXmlCharValue(int charval) {
        return charval == 0x0009 || charval == 0x000A || charval == 0x000D
                || (charval >= 0x0020 && charval <= 0xD7FF)
                || (charval >= 0xE000 && charval <= 0xFFFD)
                || (charval >= 0x10000 && charval <= 0x10FFFF);
    }
Collect a set of attribues and values from the data part of a PI.

<p>
The bulk of this method and associated methods that follow it here are
copied from the nu.validator.htmlparser.impl.Tokenizer class, with
appropriate modifications.
</p>

@see nu.validator.htmlparser.impl.Tokenizer
@see nu.validator.htmlparser.impl.ErrorReportingTokenizer
src/nu/validator/checker/XmlPiChecker.java