New XPath implementation

The old implementation was based on lpeg and
matched the grammar given in the xpath spec 1:1
(in theory). But it was so awful slow, that it
needed a re-implementation based on classic
parsing technologies. With that, pretty much
everything changed.
Fix underline, bold, and italic from non-text

When we have <U><Value select="$var" /></U> the
text did not get underlined.

Still not working for <B><I><Value .../></I></B>
Fix non-working decode-html

cross fingers that this simple code really fixes
the problem.