DtSvc/dtwm: Fix some implicit declarations of functions by adding appropriate

Patch from Frederic Koehler <f.koehler427@gmail.com>:

These implicit definitions cause segfaults on x64 because
the implicit return type is a 32-bit signed int, rather than a pointer
type.

cde/programs/dtwm/Button.c

@@ -38,6 +38,7 @@ static char SCCSID[] = "OSF/Motif: @(#)Button.c	1.19 95/05/01";
 #include <X11/cursorfont.h>
 #include "ButtonP.h"
 #include <Xm/ManagerP.h>
+#include <Xm/DrawP.h>
 #include <Dt/Control.h>
 #include <Dt/MacrosP.h>
 #include <Dt/DtStrDefs.h>

cde/programs/dtwm/UI.c

@@ -59,6 +59,7 @@
 #include <Xm/SeparatoG.h>
 #include <Xm/DialogS.h>
 #include <Xm/ColorObjP.h>
+#include <Xm/TextF.h>
 
 #include <X11/Xatom.h>
 #include <X11/keysymdef.h>

cde/programs/dtwm/WmInitWs.c

@@ -81,6 +81,7 @@ typedef struct
 #include <Dt/DtP.h>
 #include <Dt/Message.h>
 #include <Dt/WsmM.h>
+#include <Dt/EnvControlP.h>
 #endif /* WSM */
 
 /* Busy is also defined in the BMS  -> bms.h. This conflicts with

cde/programs/dtwm/WmProperty.c

@@ -54,6 +54,7 @@ static char rcsid[] = "$TOG: WmProperty.c /main/7 1997/12/02 10:00:00 bill $"
 #include "WmColormap.h"
 #include "WmError.h"
 #include "WmResParse.h"
+#include "WmIconBox.h"
 
 
 

cde/programs/dtwm/WmWrkspace.c

@@ -41,6 +41,7 @@ static char rcsid[] = "$XConsortium: WmWrkspace.c /main/7 1996/10/23 17:26:33 rs
 #include "WmGlobal.h"
 #include "WmHelp.h"
 #include "WmResNames.h"
+#include "WmIPlace.h"
 #include <X11/Xutil.h>
 #include "WmICCC.h"
 #include <Xm/Xm.h>