Updated xml-security-c package fixes multiple security vulnerabilities

The implementation of XML digital signatures in the Santuario-C++ library is vulnerable to a spoofing issue allowing an attacker to reuse existing signatures with arbitrary content (CVE-2013-2153). A stack overflow, possibly leading to arbitrary code execution, exists in the processing of malformed XPointer expressions in the XML Signature Reference processing code (CVE-2013-2154). A bug in the processing of the output length of an HMAC-based XML Signature would cause a denial of service when processing specially chosen input (CVE-2013-2155). A heap overflow exists in the processing of the PrefixList attribute optionally used in conjunction with Exclusive Canonicalization, potentially allowing arbitrary code execution (CVE-2013-2156). The attempted fix to address CVE-2013-2154 introduced the possibility of a heap overflow, possibly leading to arbitrary code execution, in the processing of malformed XPointer expressions in the XML Signature Reference processing code (CVE-2013-2210).