* Added support for HTTP authorization. (contributed by GitHub user mbr)
* Added support for registration with an existing key. (contributed by GitHub user haddoncd)
* Using an existing CSR no longer requires the private key. (contributed by GitHub user eroen)
* Fixed handling of recycled authorizations: if a domain is already authorized, the server no longer allows reauthorizing it until expired.
* Existing EC keys can now be used to issue certificates. (Support for generating EC keys is not yet implemented.)
* The authorization command now outputs proper DNS record lines.
* Private key files are now created with read permission for the owner only (`0600` mode).
* The README is now converted into reStructuredText for display in PyPI.
* Classified as Python 3 only in PyPI.