dtfile: Add missing prototypes

Add missing prototypes and header files to the dtfile
code in order to move closer towards 64-bit compatibility.

Extract the following functions from Motif internal headers:

_XmGetWidgetExtData
_XmRecordEvent
_XmStringUngenerate
_XmTextFieldSetDestination
_XmGetActiveTopLevelMenu

Extract manually prototypes of the obsolete Motif interface:
_XmHighlightBorder
_XmUnhighlightBorder

Remove XmPrivate.h if extractprototype.awk fails

Make the following header files available via -I:
	codelibs/boolean.h
	codelibs/pathutils.h
	codelibs/shellutils.h
and remove shellutils.h from dtwm directory.

cde/programs/dtfile/dtcopy/main_dtcopy.c

@@ -61,6 +61,8 @@
 #include <X11/Intrinsic.h>
 #include <X11/StringDefs.h>
 #include <Xm/Xm.h>
+#include <Xm/Text.h>
+#include <Xm/TextF.h>
 
 /* #Include <X11/Xmu/Editres.h> */      /* for editres debugging tool */
 
@@ -758,7 +760,7 @@ InitNlsMessage(void)
  * Main
  *------------------------------------------------------------------*/
 
-void
+int
 main(int argc, char *argv[])
 {
   char msg[1024];