* 2.1.1 - Jun 4 2017
- Add a lot of comments explaining what is going on
- Rename some variables to make things more clear

* 2.0.0 - Mar 23 2016
- Add VersionString
- Switch example "cmp" method which is not supported in python3 to using key=VersionString which works in either.
- Address issue where a version '.9' did not equal '0.9', by inserting an implicit '0' into comparison before or after head/tail dot
- Force string in cmp_version to that integer versions don't mess up comparison, and VersionString doesn't recurse
