Adding in a provider method to an xml assertion in order for the assertion to
be signed without the entire message being signed.
Moving the key_info data from the key_descriptor namespace. The saml 2.0
reference doc says that x509 can optionally be set inside assertion elements.
This guarantees that the certificate gets passed along with the assertion
whenever it is signed in absense of the entire saml response being signed.
Merge branch 'master' of github.com:jonathan/libsaml into jonathan-master
removed duplication