Add support for testing supported platforms under Tox.

Includes default 'setup.py test' runs for Python 2.6 / 2.7, plus a
nose + coverage run and a 'sphinx-build' run (both HTML and doctests).

tox.ini

@@ -0,0 +1,56 @@
+[tox]
+envlist = 
+#   py26,py27,py32,py33,pypy,coverage,docs
+    py26,py27,coverage,docs
+
+[testenv]
+deps =
+    zope.interface
+    zope.testing
+    manuel
+    transaction
+    persistent
+    BTrees
+    zc.lockfile
+    ZConfig
+    zdaemon
+commands = 
+    python setup.py test -q
+
+[testenv:coverage]
+basepython =
+    python2.6
+commands = 
+    nosetests --with-xunit --with-xcoverage
+deps =
+    zope.interface
+    zope.testing
+    manuel
+    transaction
+    persistent
+    BTrees
+    zc.lockfile
+    ZConfig
+    zdaemon
+    nose
+    coverage
+    nosexcover
+
+[testenv:docs]
+basepython =
+    python2.6
+commands = 
+    sphinx-build -b html -d docs/_build/doctrees docs docs/_build/html
+    sphinx-build -b doctest -d docs/_build/doctrees docs docs/_build/doctest
+deps =
+    zope.interface
+    zope.testing
+    manuel
+    transaction
+    persistent
+    BTrees
+    zc.lockfile
+    ZConfig
+    zdaemon
+    Sphinx
+    repoze.sphinx.autointerface