Set comments to 0.

Since comments are usually 0, just force them to that value; this
improves rmlse by about .08. On the test set, this moves my score
up by 0.07956 to 0.81196.
Adding some notes about working in R.

Just a few notes showing the distribution of the data in R.
Add debug information from rmsle output.

Print rowdata that shows how far off the result is from truth
as a CSV file.