Mantissa

- Mantissa is now officially supported on PyPy.
- Expired web sessions are now actually cleaned up.
- Certificate creation now uses ``cryptography``.
- SSH key management now uses ``cryptography`` instead of ``PyCrypto``.
- The Mantissa SSH server key can now be rotated with the use of the
``axiomatic mantissa ssh keyrotate`` command; it is strongly recommended to
do this for any existing Mantissa sites, as key generation previously
generated 1024-bit RSA keys which are insecure.
- Any domain for which an internal user exists will now be recognized as a
canonical hostname, allowing for relative/path-absolute URL generation.

- Remove unused ``nevow.livepage`` support code; fixes compatibility with
Nevow 0.13.0.
- ``StringEndpointPort`` ports are now deletable from the commandline (with
the ``axiomatic port delete`` command).
- Mantissa's CI now tests against Twisted trunk, for early warnings of
breakage.

- StringEndpointPort was still broken, somehow. It really works now, promise!

- Fix a major issue with the last few releases which resulted in a number of
static files not being installed and/or missing from the source tarball.
- Somewhat related to the previous issue, the tests no longer fail when
running from an installed copy due to the documentation / examples being
missing (these are not installed into site-packages).

- Fix some issues with the new StringEndpointPort which, among other things,
rendered it completely broken.
- Fix a test failure on versions of Twisted with the new logging system.

- Fix the JavaScript function for linkifying a block of text so that it
doesn't drop all the text following the last link in the text.
- Fix compatibility with modern versions of Twisted.
- Fix compatibility with modern versions of cssutils.
- Add a new port type, StringEndpointPort, which is now used by
``axiomatic port``. This now allows using any endpoint type supported by
the string endpoint parser in Twisted (which is extensible through
plugins).
- PyPy is now supported and should be fully functional (although there has
not been much real-world testing of this yet).
- Switch to setuptools; pip installation should be much easier now.