XInclude and other stuff while travelling. Contributed patches:
- tree.[ch] xinclude.[ch] xmllint.c configure.in valid.c
  debugXML.c xmlversion.h.in: Started adding XInclude support,
  this is a new xmllint option
- tree.c xpath.c: applied TOM patches for XPath
- xpointer.c: fixed a couple of errors.
- uri.c: added an escaping function needed for xinclude
- testXPath.c hash.c HTMLtree.c: minor cleanups raised by
  new warning from RH70 gcc's version
Daniel
diff --git a/configure.in b/configure.in
index df3b7e3..dde419b 100644
--- a/configure.in
+++ b/configure.in
@@ -286,6 +286,19 @@
 AC_SUBST(WITH_XPTR)
 AC_SUBST(XPTR_OBJ)
 
+AC_ARG_WITH(xinclude, [  --with-xinclude         Add the XInclude support (on)])
+if test "$with_xinclude" = "no" ; then
+    echo Disabling XInclude support
+    WITH_XINCLUDE=0
+    XINCLUDE_OBJ=
+    with_xinclude="no"
+else    
+    WITH_XINCLUDE=1
+    XINCLUDE_OBJ=xinclude.o
+fi
+AC_SUBST(WITH_XINCLUDE)
+AC_SUBST(XINCLUDE_OBJ)
+
 AC_ARG_WITH(iconv, [  --with-iconv            Add the ICONV support (on)])
 if test "$with_iconv" = "no" ; then
     echo Disabling ICONV support