Apache XML Security for C++ 1.3.1 release notes

• Initial support for API changes in Xerces 3.0 Committed by BL.
• Fix bug in autoconf that would prevent proper detection of Xerces ability to set Id attributes Committed by BL.
• Fix bug 40085 - incorrect OIDs on non SHA1 based RSA sigs Committed by BL.
• Remove redundant code in SignedInfo that was preventing the loading of signatures with algorithms not hard coded Committed by BL.
• Fix bug in Envelope transform Committed by BL.
• Fix bug in DSIGXPathFilterExpr with non-initalised vars. Reported by Ralf "Sabo" Saborowski. Committed by BL.
• Refactor NIX build to use automake and libtool Committed by BL.