Epsilon

Major:

- Python 3 is now supported.

Minor:

- Make ``epsilon.benchmark`` handle ``/proc/self/mounts`` more leniently.

Minor:

- Fix ``epsilon.benchmark`` compatibility with newer *Twisted* versions.
- Add explicit dependency on ``zope.interface``.

Major:

- *certcreate* should now be installed properly.
- An ``asRFC1123`` method was added to ``extime.Time``.
- As *Twisted* is dropping Python 2.6, Epsilon will also not support 2.6 from
the next release.

Minor:

- ``epsilon.benchmark`` now uses ``/proc/self/mounts`` instead of relying on
``/etc/mtab`` which is often wrong, or does not even exist.
- Fixed a test that interacted badly with *Twisted* 15.4.0.
- Updated the metadata in *setup.py*.

Major:

- Only *Python* 2.6 and 2.7 are supported now. 2.4, 2.5 is deprecated.
- setup.py now uses setuptools, and stores its dependencies. This
means you no longer need to manually install dependencies.
- *setup.py* no longer requires *Twisted* for *egg_info*, making it easier
to install *Epsilon* using *pip*.
- Significant improvements to *PyPy* support. *PyPy* is now a supported
platform, with CI support.
- ``epsilon.release`` is now removed. It relied on a bunch of machinery
specific to *Divmod* that no longer existed.
- ``epsilon.sslverify`` is now removed. Use ``twisted.internet.ssl`` instead.
- ``epsilon.asTwistedVersion`` takes a string version (``"1.2.3"``) and
turns it into a ``twisted.python.versions.Version``.

Minor:

- Several deprecation warnings have been cleaned up.

- Disable loopback hotfix on *Twisted* 8.2 and newer.
- Remove the implementation of ``Cooperator`` and use *Twisted*'s
implementation instead.
- Use *Twisted*'s ``deferLater`` implementation.
- Add a service for communicating via *stdio*.
- Add a ``precision`` argument to ``Time.asHumanly`` to control the precision
of the returned string.