Cosmetic Refactoring & Changed Tests to new API

Howdy,

I've been reviewing the code and test suite in preparations for some larger changes which we're planning ot make.  This pull includes three adjustments:
- Cosmetic refactoring (changing order of lines, indentation, whitespace, comments)
- Completely redid Roo::Base.number_to_letter  Tests still pass
- Adjusted tests to use the new options hash, reducing the number of warnings thrown when running the suite.

Let me know if you have any questions.