allow toggling of software back menu item. add recovery checkpoint file. mount auto now uses busybox mount.
diff --git a/common.h b/common.h
index 81d9029..6c60d07 100644
--- a/common.h
+++ b/common.h
@@ -47,6 +47,9 @@
 // statements will be displayed.
 void ui_end_menu();
 
+int ui_get_showing_back_button();
+void ui_set_showing_back_button(int showBackButton);
+
 // Set the icon (normally the only thing visible besides the progress bar).
 enum {
   BACKGROUND_ICON_NONE,