* Added prune command-line option.
* Updated stats to separate mssing and bad.
* Added function to add tuples - makes code more legible.
* Moved KeyboardInterrupt try/catch to outside of while loop so that it actually stops the crawl.
* Need to add a throw/try/catch to pop out of process_root! If multiple roots specified, only the current one will be aborted.
* Implemented file pruning.
* Started on dir pruning.
* Cleaned up/reorganized TODO.TXT.
Working on pruning directories.