[XOM-interest] XOM and C14N 1.1

[Elliotte Rusty Harold]

I've checked in the initial support for Canonical XML 1.1 into the
repository. I'm not sure how accurate this is. So far I've run one
test case, and also verified that my old test cases still pass. It
would be helpful if someone had a clear list of the differences
between C14N 1.0 and C14N 1.1.

[Elliotte Rusty Harold]

After a day of hacking, the basics are in place for Canonical XML 1.1
support in head. The canonicalization test cases from
http://www.w3.org/TR/2008/NOTE-xmldsig2ed-tests-20080610/#c14n11xmlbase-c14n11spec-102
all pass though I still need to verify the XML Base fixup examples in
Appendix A. There may well be corner cases I missed. Indeed while
implementing I found one major corner case that is not covered by the
official test suite. However most documents likely to be encountered
in practice should be properly handled.

Once I get around to verifying the Appendix A examples, I'll release
this as XOM 1.2.7. In the meantime you can check it out of head.