Option to set static 'end of text' code

Issue Summary

Verizon changed there text to something new which of course stopped the cleanup from happening.

So I was wondering if there would be any interest to have the option to set a static 'End of Text' code. This would eliminate the need to constantly update the text based on whatever the phone company chooses to use that day.

Alternatively it could be used, instead of an option, as the default setting for the cleanup, which would allow us to change the text in the settings verses needing to update the code.

Any thoughts? I may put a patch together as an example sometime this upcoming weekend.