Consider structure of project for maintainability

[srpeirce]

We have ElementExtensions, RenderedFragmentExtensions.

Currently code and tests for a feature are split across these three classes and quite seperate.

I'm wondering if it would be better to change mind and group features...e.g. keep all .ShouldHaveClass extensions together regardless of what they are extending.

Might add a couple more features to make sure I'm not prematurely changing things.....

I welcome feedback on this thought...

[srpeirce]

Will leave this until implemented #4