Fix the logging error

Fixes conda#165.

You have to have a no-op logging handler. See
http://docs.python.org/3.1/library/logging.html#configuring-logging-for-a-library.

conda/install.py

@@ -72,6 +72,19 @@ def win32link(src, dst):
 
 log = logging.getLogger(__name__)
 
+class NullHandler(logging.Handler):
+  """ Copied from Python 2.7 to avoid getting
+      `No handlers could be found for logger "patch"`
+      http://bugs.python.org/issue16539
+  """
+  def handle(self, record):
+    pass
+  def emit(self, record):
+    pass
+  def createLock(self):
+    self.lock = None
+
+log.addHandler(NullHandler())
 
 def _link(src, dst):
     try: