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/FileMgr.c

@@ -106,6 +106,7 @@
 #include <pwd.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <ctype.h>
 
 #include <Xm/XmP.h>
 #include <Xm/CascadeB.h>
@@ -142,6 +143,8 @@
 #include <Dt/HourGlass.h>
 #include <Dt/DtNlUtils.h>
 #include <Dt/Dts.h>
+#include <Dt/SharedProcs.h>
+#include <Dt/Wsm.h>
 
 #include <Xm/DragIcon.h>
 #include <Xm/DragC.h>
@@ -163,6 +166,7 @@
 #include "Prefs.h"
 #include "SharedMsgs.h"
 #include "IconicPath.h"
+#include "DtSvcInternal.h"
 
 
 /*  Dialog classes installed by Main.c  */