Major: Change converter, gurantee a 22 digit short form

The converter now uses only digits and lower- and uppercase letters for
encoding a UUID.
Also, it ensures UUIDs with leading zeros will be converted properly by
adding leading zeros to the short format.
The short form now always consists of 22 characters.
Release version 0.1.0, major converter changes

Converter now ensures that converted UUID has exactly 22 characters.