fix conftest related fixture visibility issue: when running with a

CWD outside a test package pytest would get fixture discovery wrong.
Thanks to Wolfgang Schnerring for figuring out a reproducable example.

--HG--
branch : conftest-nodeid

setup.py

@@ -27,7 +27,7 @@ def main():
         name='pytest',
         description='pytest: simple powerful testing with Python',
         long_description=long_description,
-        version='2.6.3.dev',
+        version='2.6.3.dev3',
         url='http://pytest.org',
         license='MIT license',
         platforms=['unix', 'linux', 'osx', 'cygwin', 'win32'],