Porting libxml2 on zOS encoding of code

First set of patches for zOS
- entities.c parser.c tree.c xmlschemas.c xmlschemastypes.c xpath.c xpointer.c:
  ask conversion of code to ISO Latin 1 to avoid having the compiler assume
  EBCDIC codepoint for characters.
- xmlmodule.c: make sure we have support for modules
- xmlIO.c: zOS path names are special avoid dsome of the expectstions from
  Unix/Windows

xmlschemastypes.c

@@ -7,6 +7,11 @@
  * Daniel Veillard <veillard@redhat.com>
  */
 
+/* To avoid EBCDIC trouble when parsing on zOS */
+#if defined(__MVS__)
+#pragma convert("ISO8859-1")
+#endif
+
 #define IN_LIBXML
 #include "libxml.h"