[Help-smalltalk] expat bindings committed

[Paolo Bonzini]

Hi all, I committed some Expat bindings.  I had meant to do them for 
literally years, but I got to it only now that Antony Blakey and Ken 
Treis's XMLPullParser provided the basic infrastructure and a few unit 
tests.

Compared to the original pull parsers, all SAX events have class 
counterparts and can be obtained by the pull parser.  Also, by using 
Generators it is possible to make a very fast pull parser (like Ken's) 
that is also pluggable (like Antony's).

Paolo