More modular unit testing

[jagerber48]

Many of the tests are more like integration than unit tests. While these are valuable and demonstrate good usage example, I think it would help the organization and usefulness of the tests if there were more modular unit tests. e.g. testing the functionality of the various formatting utilities, or the construction of format options classes from the FSML.

[jagerber48]

This issue begins to be addressed by #158 which sorts tests into unit tests and feature tests. That sorting revealed that almost all of the tests are feature tests. There is very little unit testing. This issue is a call for more unit testing.

[jagerber48]

More unit tests can still be added after #161