only invoke distribute's use_setuptools when there is no setuptools installed

setup.py

@@ -1,5 +1,9 @@
 import os, sys
-if sys.version_info >= (3,0):
+try:
+    from setuptools import setup
+except ImportError:
+    if sys.version_info < (3,0):
+        raise
     from distribute_setup import use_setuptools
     use_setuptools()
     from setuptools import setup

tox.ini

@@ -4,7 +4,7 @@ envlist=py26,py27,py31,py32,py27-xdist,py25,py24
 indexserver=
     pypi = http://pypi.python.org/simple
     testrun = http://pypi.testrun.org
-    default = http://pypi.testrun.org
+    default = http://pypi.python.org/simple
 
 [testenv]
 changedir=testing