[11u] RFR(S): 8232357: Compare version info of Santuario to legal notice

[Lindenmaier, Goetz]

Hi,

I want to downport this for parity with 11.0.8-oracle.

Unfortunately the test uses Files.mismatch(), which is not
available in 11.
I copied the implementation of that method into the test
which fixes the issue.
Also, the comment is already there in XMLDSigRI.java, so
I omitted that:
http://hg.openjdk.java.net/jdk-updates/jdk11u-dev/file/1e534c8cf25c/src/java.xml.crypto/share/classes/org/jcp/xml/dsig/internal/dom/XMLDSigRI.java#l138

Please review.
http://cr.openjdk.java.net/~goetz/wr20/8232357-Santuario_test-jdk11/01/

Original change:
https://bugs.openjdk.java.net/browse/JDK-8232357
https://hg.openjdk.java.net/jdk/jdk/rev/7322c48a84cf

Best regards,
  Goetz