Added text option for number-display

This will allow users to set the text attached with a number-display. (TO DO) Pluralization of text, (https://github.com/blakeembrey/pluralize) can be helpful.
This is too complicated a way to force a value of 0 or 1, and will just confuse the reader.  You don't need to change the reduction at all - instead you can just have the accessor return 0 or 1.