Simple ABBYY XML to CSV converter.

This does not do anything special. It simply spews everything out into a
CSV file, without regard for columns or rows or pages.
Fix PDF conversion parameter defaults.
Use clustering to get text into lines.
Add code license.
Use clustering to make columns as well.
Remove scaler on cluster inputs.

Should be possible to just tweak the thresholds to achieve similar
results.
Ensure columns and rows are correctly sorted.
Save page and bounding box for each row.
Refactor processor and command-line argument parser.
Add Readme information.