FvwmPager: respect DesktopConfiguration setting

When FvwmPager is launched without a "Monitor" config, it assumes the
remit is global -- that is, it will show windows from all monitors.
However, this could be at odds with the DesktopConfiguration setting.

When FvwmPager performs tasks such as switching pages and/or desks, it
does so by sending Fvwm commands directly.  This includes monitor
information which is not what's needed if DesktopConfiguration is
global.

Therefore, only send the monitor string across if FvwmPager is already
tracking a specific monitor.

Helps with fvwmorg#236

modules/FvwmPager/x_pager.c

@@ -1903,7 +1903,9 @@ void SwitchToDesk(int Desk)
 	char command[256];
 	struct fpmonitor *m = fpmonitor_this();
 
-	sprintf(command, "GotoDesk %s 0 %d", m->name, Desk + desk1);
+	sprintf(command, "GotoDesk %s 0 %d", monitor_to_track ? m->name : "",
+			Desk + desk1);
+	fprintf(stderr, "%s: cmd: %s\n", __func__, command);
 	SendText(fd,command,0);
 }
 
@@ -1921,7 +1923,9 @@ void SwitchToDeskAndPage(int Desk, XEvent *Event)
     vy = Event->xbutton.y * mon->virtual_scr.VHeight / (desk_h * mon->virtual_scr.MyDisplayHeight);
     mon->virtual_scr.Vx = vx * mon->virtual_scr.MyDisplayWidth;
     mon->virtual_scr.Vy = vy * mon->virtual_scr.MyDisplayHeight;
-    sprintf(command, "GotoDeskAndPage %s %d %d %d", mon->name, Desk + desk1, vx, vy);
+    sprintf(command, "GotoDeskAndPage %s %d %d %d",
+		monitor_to_track ? mon->name : "", Desk + desk1, vx, vy);
+    fprintf(stderr, "%s: cmd: %s\n", __func__, command);
     SendText(fd, command, 0);
 
   }
@@ -1941,8 +1945,8 @@ void SwitchToDeskAndPage(int Desk, XEvent *Event)
       x = mon->virtual_scr.VxMax / mon->virtual_scr.MyDisplayWidth;
     if (y * mon->virtual_scr.MyDisplayHeight > mon->virtual_scr.VyMax)
       y = mon->virtual_scr.VyMax / mon->virtual_scr.MyDisplayHeight;
-    sprintf(command, "GotoPage %s %d %d", mon->name, x, y);
-    fprintf(stderr, "%s: going to page: %s %d, %d\n", __func__, mon->name, x, y);
+    sprintf(command, "GotoPage %s %d %d", monitor_to_track ? mon->name : "", x, y);
+    fprintf(stderr, "%s: cmd: %s\n", __func__, command);
     SendText(fd, command, 0);
   }
   Wait = 1;
@@ -1954,9 +1958,10 @@ void IconSwitchPage(XEvent *Event)
   struct fpmonitor *mon = fpmonitor_this();
 
   sprintf(command,"GotoPage %s %d %d",
-	  mon->name,
+	  monitor_to_track ? mon->name : "",
 	  Event->xbutton.x * mon->virtual_scr.VWidth / (icon_w * mon->virtual_scr.MyDisplayWidth),
 	  Event->xbutton.y * mon->virtual_scr.VHeight / (icon_h * mon->virtual_scr.MyDisplayHeight));
+  fprintf(stderr, "%s: cmd: %s\n", __func__, command);
   SendText(fd, command, 0);
   Wait = 1;
 }