Added rebalancing script.
Added zookeeper cleanup script.
Addressed comments in pull request.
Removed check on the wrong host, fix arithmetic.
Repair only one node at a time.
Fixed script for cassandra 2.1.
Clean up script.

Made the math a bit more obvious, and added more checks.
Fix typo.
Fixed comment.
Don't re-use tokens during assignments.
Deal with some nodes not having sample keys yet.
Dealing with Cassandra 2.1.
Fixed wrong logic.
Fix command line invocation for cassandra 2.1.
Simplified the script, and added error checks.
Moved removal of decimal point up.
Needed to move ssh outside main loop.

Some issue with the shell redirection confused the loop otherwise.
Added a separate script to clean nodes.
Added -parallel option.
Added parallel option.