Add a way to change button title to "Save before exiting" when using custom categories

[fifth-light]

Sorry for my poor English.
I'm using YACL's custom category in some part of my options screen in my mod TouchController. I recreated save & undo & reset buttons in my custom category. But when Escape key pressed with unsaved changes, there is no way to detect this event to change the title of save button to the red text "Save before exiting", so nothing happened. Could you please change the API of CustomTabProvider to provide a way to detect such event?