Add version tracking information

[kiwistrongis]

SMT.revision is an integer tracks the revision. It should always be greater than all previous releases. It is equivalent with the version variable in [library.properties].

SMT.version is a string that tracks the release of SMT. It is equivalent with the prettyVersion variable in [library.properties] as well as the git tag for the same release ( with the exception of the preceding 'v' in git tags ).

SMT.version_pretty is a human-readable version of SMT.version. It should include alpha and beta information.

SMT.getRevision(), SMT.getVersion(), and SMT.getPrettyVersion() get SMT.revision, SMT.version, and SMT.version_pretty, respectively.

[kiwistrongis]

done as of 0487400