Class to control the URM37 via serial

Thanks for the tip, I'll update that if/when moved to library form.

I created a simple library but feel I should use it some before posting.

I really do not like the duplicate functions. I created this in a couple hours to create an interactive light bar. I'll work out how to reference a pointer to the correct serial instance or at least break out duplicate function into a single routine before posting as a library.

Other feedback welcome.