The logger expects a NullHandler instance, not a class. Otherwise, if you run
this in an environment without a logger already set up, it raises an
AttributeError as 'level' is defined on the instance, not the class.

Changes since v0.0.3:
- pytest-localserver is now Py3 compatible (#3, thanks redtoad)
- restored Python 2.6 compatibility (#2)

Changes since v0.0.2:
- break Python 2.6 compatibility
- change logging to
  http://docs.python.org/dev/howto/logging.html#library-config

No more aptitude or command concatenation

I disagree about the terribleness, but namespacing is a good idea.

From http://docs.python.org/dev/library/logging.html#logging.basicConfig

> The functions debug(), info(), warning(), error() and critical() will
> call basicConfig() automatically if no handlers are defined for the
> root logger.

> This function does nothing if the root logger already has handlers
> configured for it.

Calling `logging.debug()` directly causes a `logging.StreamHandler` to be added to the default root logger `logging.getLogger()`.

This has terrible consequences when one wants to keep control over the handlers of the root logger.

The proposed change fixes that issues while keeping the log output if needed.

Test this, both in strict and relaxed mode.

Also add more tests.

Also add better error handling, and tests for strict and relaxed
behaviour.

That means switching from nose to pytest.

pytest-localserver is a pytest plugin providing an http server
stub. The plugin doesn't work with Python3 however, and has to
be blacklisted in tox.

I'm not sure how this relates to other mime uses, like e-mail.

2to3 is enabled by switching to Distribute from distutils.

LEPL now works on character strings; I'd prefer byte strings,
but this seems to work.

The bugs happened when Content-Disposition isn't defined.