title: GtkEntry select region seems to do nothing
body: <p>It's my first times with GTK library, I wrote this code:</p>
  
  <pre><code>GtkWidget *dialog, *vbox;
  /* create dialog */
  dialog = gtk_dialog_new_with_buttons("Go to File...", GTK_WINDOW(parent),
  GTK_DIALOG_DESTROY_WITH_PARENT, GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
  GTK_STOCK_OK, GTK_RESPONSE_ACCEPT, NULL);
  
  gtk_widget_set_name(dialog, "GotoFile");
  vbox = ui_dialog_vbox_new(GTK_DIALOG(dialog));
  
  GtkWidget *label = gtk_label_new("Enter the file you want to open:");
  
  gtk_container_add(GTK_CONTAINER(vbox), label);
  
  /* create entry */
  GtkWidget *entry = gtk_entry_new();
  gtk_container_add(GTK_CONTAINER(vbox), entry);
  gtk_entry_set_text(GTK_ENTRY(entry), "this_is_a_test");
  gtk_entry_set_max_length(GTK_ENTRY(entry), MAX_FILENAME_LENGTH);
  gtk_entry_set_width_chars(GTK_ENTRY(entry), 30);
  gtk_editable_select_region(GTK_EDITABLE(entry), 2, 5);
  </code></pre>
  
  <p>I expect it creates a dialog with a label and textbox (and this is working) and selects characters "is_" into the entry, but it's not working (all text is selected).</p>
  
  <p>I tried also:</p>
  
  <pre><code>gint a,b;
  gtk_editable_get_selection_bounds(GTK_EDITABLE(entry), &amp;a, &amp;b);
  
  printf("SELECTION: %i - %i\n",a,b);
  </code></pre>
  
  <p>And it prints correctly 2 and 5.</p>
  
  <p>What's wrong?</p>