Update tox tests so they run the full suite of tests using the canonical...

Update tox tests so they run the full suite of tests using the canonical technique. Include .tox in norecursedirs to avoid testing all the dependencies and environment. Update docs to reflect findings (https://bitbucket.org/spookylukey/setuptools/commits/88339d2e4af661a60a42bc14c4ff3e68cd19fa21#comment-2558164).

docs/developer-guide.txt

@@ -94,7 +94,8 @@ The primary tests are run using py.test. To run the tests::
 
     $ python setup.py test
 
-Or install py.test into your environment and run ``py.test``.
+Or install py.test into your environment and run ``PYTHONPATH=. py.test``
+or ``python -m pytest``.
 
 Under continuous integration, additional tests may be run. See the
 ``.travis.yml`` file for full details on the tests run under Travis-CI.

tox.ini

 [tox]
 envlist = py26,py27,py31,py32,py33,py34
+
 [testenv]
-deps=
-    pytest
-    mock
-commands=py.test setuptools {posargs}
+commands=python setup.py test