Hack the xml2-config to return paths into WORKDIR.

--- a/xml2-config.in	2009-12-17 11:45:20.000000000 +0000
+++ b/xml2-config.in	2009-12-17 11:45:36.000000000 +0000
@@ -1,9 +1,14 @@
 #! /bin/sh
 
-prefix=@prefix@
-exec_prefix=@exec_prefix@
-includedir=@includedir@
-libdir=@libdir@
+#prefix=@prefix@
+#exec_prefix=@exec_prefix@
+#includedir=@includedir@
+#libdir=@libdir@
+
+prefix=${WORKDIR}/UnpackedTarball/libxml2
+exec_prefix=${WORKDIR}/UnpackedTarball/libxml2
+includedir=${WORKDIR}/UnpackedTarball/libxml2/include
+libdir=${WORKDIR}/UnpackedTarball/libxml2/.libs
 cflags=
 libs=
 
@@ -67,7 +72,8 @@
 	;;
 
     --cflags)
-        cflags="@XML_INCLUDEDIR@ @XML_CFLAGS@"
+        #cflags="@XML_INCLUDEDIR@ @XML_CFLAGS@"
+        cflags="-I${includedir}"
        	;;
 
     --libtool-libs)
@@ -91,7 +96,8 @@
             libs="@XML_LIBDIR@ $libs"
         fi
 
-        libs="$libs @WIN32_EXTRA_LIBADD@"
+        #libs="$libs @WIN32_EXTRA_LIBADD@"
+        libs="-L${libdir} -lxml2 -lm"
         ;;
 
     *)