v4.0.0-alpha.3

This release fixes #5 and two minor issues: #49 and #55. It also incorporates numerous fixes to the code and in general is pretty stable. It is still an alpha release and there are known issues, either stored in TODOs and FIXMEs in the code or in the issue tracker on GitHub.

At this point, the code should be mature enough that it can for most purposes replace the Bash script.