Detox

- get compatible again to tox-2.0

- get compatible again to eventlet by avoiding to import
eventlet.processes, thanks Takeshi Komiya for the PR.
- make detox honor skipsdist. Thanks Timoth Messier for the PR.
- change license to MIT

- fix issue6: quickly make detox work with tox-1.6 again (although not
all 1.6 features supported, e.g. --develop does not work)
- fix issue3: don't claim a TROVE identifier of "python3" because
detox itself depends on eventlet which does not work on py3 yet.
(Nevertheless detox will create py3 environments through tox of
course)
- fix issue1: support python2.5 again (although we might drop it in
the future -- it's enough of tox/detox can _[create]() and handle
py25 environments, they don't neccessarily need to support running
themselv on py25)

- fix issue4 - fail properly if sdist-packaging fails

- fix issue5 - small adjustments to work with latest tox-1.4.3 version

- initial release