Log Message:
1.5.3:
Bugfix
[CPPXT-92] - Update xmlsig 1.1 schema to final CR

Improvements
[CPPXT-94] - Configuration check should check for missing private key
[CPPXT-95] - Improve logging when libcurl is built without OpenSSL

1.5.2:
Bugfixes
[CPPXT-89] - Regression in deprecated catalog_path option during initialization
[CPPXT-90] - X509Digest generates base64 based on hex digest instead of binary

Improvement
[CPPXT-91] - KeyInfoResolver code returns empty credential object.

1.5.1:
Improvement
[CPPXT-88] - Support path resolution in ParserPool / catalog files

1.5.0:
Bugfixes
[CPPXT-76] - Remove compile time version output where possible.
[CPPXT-79] - link fails if xml-security-c library outside default link path
[CPPXT-83] - Transport layer not handling Last-Modified header correctly
[CPPXT-84] - Problems compiling log4shib on Solaris SPARC 10 with Sun
             Studio 12.1 with 64bit libraries
[CPPXT-86] - Small Memory Leak in XMLObjectBuilder::buildFromElement()

Improvements
[CPPXT-70] - Improve remote CRL access and caching support
[CPPXT-78] - Support configuration of name and policy restrictions for the
             signature metadata filter (signing certificate)
[CPPXT-82] - libcurl, ExplicitKeyTrustEngine, PKIX could provide additional
             debug information
[CPPXT-87] - Libcurl versions before 7.20 do not refresh caches of IdP IP
             address look-ups - this breaks SAML1 attribute query if the IdP's
             IP address is changed