Inclusive namespace support

[dheniges]

When computing the canonical assertion xml to validate a SAML response with the signature, the xml-crypto library requires a workaround for inclusive namespaces.

node-saml/xml-crypto#48

[dheniges]

I've gone ahead and created a fix for this in case anyone else needs it: mindspacepdx#1

If this lib gets active again I'll look into adding tests and PR it here

[pdspicer]

Hey, I'm trying to get things moving again, would be happy to see a PR for this with tests.

[misanche]

it would be nice to be included! the @dheniges mod works correctly