first pass at a refactor; starting with breaking down large methods into smaller
refactoring horizontal; adding tests for compute_rows_cols_and_width
refactoring horizontal.rb; updated logic for compute_rows_cols_and_widths to be more succinct
refactoring horizontal: final pass for now.  quite happy with how it turned out.  Also, broke apart tests in test-columnize-array.rb
started refactoring vertical.rb; it's going to be harder than horizontal, possibly
still working on understanding vertical.rb
starting to understand the relationship between rows and columns better
refactored vertical out of existance.  this pleases me.
small refactors to opts.rb
making the base columnize.rb file as basic as possible; also, started on the idea that parse_columnize_opts should return self as list if self.class has Columnize included; lastly, renamed horizontal.rb to columnize.rb since there is no longer a horizontal and a vertical function
oops, forgot to change the include statement to reflect the name change
making a commit before I completely refactor everything to use an internal class
compartmentalizing things into a Columnizer object
refactoring such that the module retains the old interface, which it delegates to the new Columnizer class; once I am happy with that class, I want to build an interface for including the module into Array (and other Array-like objects)
added a test file for columnizer to explictly test the class; moved some tests out of other files into columnizer; renamed some options to better match each other
added some convenience methods for setting list and opts, also, for updating opts
now using the passed in opts hash as an interface for the class which allows a single instance to more easily be reused; next up, freezing the @opts hash to make sure that the interface is obeyed rather than abused
have to commit with tests failing because I need to go; this is the start of the new include structure
all tests passing.  mixxin for array working (basic, but sane)
updated the demo code to work