Client version 0.4.0 has been released

[Brad Warren]

Version 0.4.0 of the Let's Encrypt client has just been released to
PyPI. This is easily the biggest client release since public beta began.
New features in this release include:

* The new verb/subcommand `renew` can be used to renew your existing
certificates as they approach expiration. Running `letsencrypt renew`
will examine all existing certificate lineages and determine if any are
less than 30 days from expiration. If so, the client will use the
settings provided when you previously obtained the certificate to renew
it. The subcommand finishes by printing a summary of which renewals were
successful, failed, or not yet due.

* A `--dry-run` flag has been added to help with testing configuration
without affecting production rate limits. Currently supported by the
`renew` and `certonly` subcommands, providing `--dry-run` on the command
line will obtain certificates from the staging server without saving the
resulting certificates to disk.

* Major improvements have been added to letsencrypt-auto. This script
has been rewritten to include full support for Python 2.6, the ability
for letsencrypt-auto to update itself, and improvements to the
stability, security, and performance of the script.

* Support for Apache 2.2 has been added to the Apache plugin.

A more complete list of changes can be found at:

https://github.com/letsencrypt/letsencrypt/issues?q=is%3Aissue+milestone%3A0.4.0