Revert "remove CFO"

This reverts commit 0418ba597b.

src/core/Frontend.h

@@ -381,6 +381,9 @@ enum eMenuAction
 #ifdef CUTSCENE_BORDERS_SWITCH
 	MENUACTION_CUTSCENEBORDERS,
 #endif
+#ifdef CUSTOM_FRONTEND_OPTIONS
+	MENUACTION_TRIGGERFUNC
+#endif
 };
 
 enum eCheckHover
@@ -475,7 +478,7 @@ struct CMenuScreen
 		int32 m_Action; // eMenuAction
 		char m_EntryName[8];
 		int32 m_SaveSlot; // eSaveSlot
-		int32 m_TargetMenu; // eMenuScreen
+		int32 m_TargetMenu; // eMenuScreen // FrontendOption ID if it's a custom option
 	} m_aEntries[NUM_MENUROWS];
 };