Turn into a library

This project was originally intended to become a library. Right now it is a seed project instead.

The [beth](https://github.com/mslinn/beth) project is built from this project. Any application-specific portions of this project should be deleted.

When this project becomes library it should be published to [BinTray](https://bintray.com/micronautics/scala/cli-loop/edit?tab=general).