Abbot versioning

The Abbot runtime uses semantic versioning (http://semver.org/). In brief:

Abbot versions are always of the form X.X.X.

• The first X is a release (a 0 indicates a pre-release version).
• The second X is some change that breaks the API. In Abbot, this includes not only the Java API, but the syntax of the configuration file.
• The third X is any patch whatsoever.

Special versions (like betas) tack some text on to the end (e.g. 1.4.35beta1, 1.5.328-rc1).