P4 to P5

[Syd Bauman]

> people may be amused to see how small a p4 to P5 instance
> converter is, in XSLT:

Well, so far, yes. But wait 'til you need to move all those CDATA
attributes into child elements ... :-)

Also we haven't come to a definitive conclusion about a version=
attribute on <TEI> (and thus it's not here in your stylesheet). I'm
inclined to say it should be required. Still not sure exactly what
form it should take.