Added month as categorical fixed effect.
Explicity convert the chr columns to ordered Factors.
Added automated model selection and a
visualization to highlight the optimal
selection.
Used the 'segments' package to determine CDH
breakpoint rather than my homegrown method.

Also created a function to support a variable
number of CDH lags.
Placed the variable CDH lag function in
its own file.

A smattering of junk code at the end currently as I write my weekly report.
Wow gross...