Quicktester

- re-release of 0.4 since the previous release was screwed up.

- tox: added tox configuration file so it's easier to run the tests
locally. This also means that the Makefile and the old runtests
script is no longer needed.
- version: added support for Python 3.5, but dropped Python 3.2.
While 3.2 is no longer officially supported, it will work a little
bit longer with it.

- contrib: small improvements to the VIM plugin
- statistics: use a global statistics file. This way you can collect
a lot of information about how you do the TDD dance. Despite this,
the statistics tool will mostly work like before, but now you can
retrieve the tests that ran under your current working directory,
even if you didn't start the tests there.
- statistics: added a few extra options (JSON output, show all tests,
etc.)

- statistics: use a new, sqlite3-based format. This statistics
file contains the passed tests as well. The old format can still
be loaded.
- git-changes: alternative mapping. This feature makes it
possible to use quicktester if your tests aren't nested
under the tested package but rather reside in a separate
path.
- git-changes: the name mapping option tries to map filenames
to their test modules. So if 'package/module.py' is changed,
'package/tests/test_module.py' is run.
- quickfix: show the exception at the beginning of a trace. This
way separating what lines belong to what exceptions are
easier to do.
- quickfix: In Python 3+, show the whole exception chain in
the quickfix file.
- Added a VIM plugin for making quicktester easier to use with it.
- Major test cleanup resulting in faster test runs.

- Initial implementation.
- git-changes plugin for testing changed files
- fail-only plugin for running previously failed files
- statistics plugin for recording failures and test runs
- quickfix plugin for displaying errors in VIM with the
quickfix feature