[libxml2]Add libxml2 library

libxml2/test/schemas/any7_1.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<!-- 
+Error reported:
+
+any-2_1.xml:17: element bar: Schemas validity error : 
+Element '{urn:test:foo}bar': This element is not expected. 
+Expected is one of ( {##other:urn:test:foo}* ).
+
+Tiny glitch: the error report mechanism fails to recognize
+that there is only one element of choice. It should report:
+"Excepted is ( {##other:urn:test:foo}* ).".
+-->
+<foo:foo xmlns:foo="urn:test:foo" xmlns:moo="urn:test:moo"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="urn:test:foo any-2_1.xsd">
+	<foo:bar/>
+	<foo:bar/>
+</foo:foo>