Added a couple of GTK mainloop calls so that the UI is updated in

a more timely fashion.  Helps with backends which have potentially
 slow sane_start() and sane_read() commands (e.g. microtek).

src/progress.c

@@ -69,6 +69,7 @@ progress_new (char *title, char *text,
   gtk_widget_show (p->pbar);
   gtk_widget_show (button);
   gtk_widget_show (GTK_WIDGET (p->shell));
+  gtk_progress_bar_update (GTK_PROGRESS_BAR (p->pbar), 0);
   return p;
 }
 

src/xscanimage.c

@@ -890,6 +890,8 @@ scan_start (void)
 
   scan_win.x = scan_win.y = 0;
 
+  while (gtk_events_pending ())
+    gtk_main_iteration ();
   status = sane_start (dev);
   if (status != SANE_STATUS_GOOD)
     {
@@ -1032,8 +1034,12 @@ scan_start (void)
       && sane_get_select_fd (dev, &fd) == SANE_STATUS_GOOD)
     scan_win.input_tag = gdk_input_add (fd, GDK_INPUT_READ | GDK_INPUT_EXCEPTION,
 					input_available, 0);
-  else
+  else 
-    input_available (0, -1, GDK_INPUT_READ);
+    {
+      while (gtk_events_pending ())
+	gtk_main_iteration ();
+      input_available (0, -1, GDK_INPUT_READ);
+    }
 }
 
 /* Invoked when the scan button is pressed */