[libxml2]Add libxml2 library

libxml2/test/c14n/1-1-without-comments/xmlbase-prop-3.xpath

@@ -0,0 +1,11 @@
+<!--
+http://www.w3.org/TR/xmldsig2ed-tests/#c14n11xmlbase-prop-3
+
+Check that implementations of [XML-C14N1.1] properly build the xml:base 
+if one of intermediate the levels (ietf:e1) are absent from the document 
+subset.
+-->
+<XPath xmlns:ietf="http://www.ietf.org" >
+(//. | //@* | //namespace::*)
+[ancestor-or-self::ietf:e11]
+</XPath>