RFR CSR 8203460: Update xmldsig implementation to latest version of Apache Santuario

[Weijun Wang]

Please take a review at

   https://bugs.openjdk.java.net/browse/JDK-8203460

The current XMLDSig provider implementation is based on Apache Santuario 1.5.4. 
We'll update it to be 2.1.1. New algorithms are added.

Thanks
Max