have core ask windowport if suspend is ok

PORTS: Please make sure I've done the right thing for/to your code.
This patch adds a new winproc that lets the window port approve or cancel
the suspend request - this should take care of the Mac Qt lockup issue.
In addition, Unix suspend is restricted to accounts that can use the shell
if SYSCF is defined.

win/X11/winX.c

@@ -173,6 +173,7 @@ struct window_procs X11_procs = {
     genl_status_threshold,
 # endif
 #endif
+    genl_can_suspend_no,	/* XXX may not always be correct */
 };
 
 /*

win/gem/wingem.c

@@ -111,6 +111,7 @@ struct window_procs Gem_procs = {
     genl_status_threshold,
 # endif
 #endif
+    genl_can_suspend_no,
 };
 
 #ifdef MAC

win/gnome/gnbind.c

@@ -90,6 +90,7 @@ struct window_procs Gnome_procs = {
     genl_status_threshold,
 # endif
 #endif
+    genl_can_suspend_yes,
 };
 
 /*  

win/tty/wintty.c

@@ -137,6 +137,7 @@ struct window_procs tty_procs = {
     genl_status_threshold,
 # endif
 #endif
+    genl_can_suspend_yes,
 };
 
 static int maxwin = 0;			/* number of windows in use */

win/win32/mswproc.c

@@ -136,6 +136,7 @@ struct window_procs mswin_procs = {
     genl_status_threshold,
 # endif
 #endif
+    genl_can_suspend_yes,
 };