[libxml2]Add libxml2 library

libxml2/test/c14n/1-1-without-comments/xmlbase-prop-7.xpath

@@ -0,0 +1,10 @@
+<!--
+http://www.w3.org/TR/xmldsig2ed-tests/#c14n11xmlbase-prop-7
+
+Check that implementations of [XML-C14N1.1] do not pass the xml:base 
+to another element when it is not necessary.
+-->
+<XPath xmlns:ietf="http://www.ietf.org" >
+(//. | //@* | //namespace::*) 
+[ancestor-or-self::ietf:c14n11XmlBaseDoc1 and not(ancestor-or-self::ietf:e1 or ancestor-or-self::ietf:e2)]
+</XPath>