Flows no longer need to be saved between uses.

Also introduces util.positional declarations.

Reviewed in http://codereview.appspot.com/6441056/.

Fixes issue #136.
diff --git a/samples/analytics/sample_utils.py b/samples/analytics/sample_utils.py
index c397bf8..10aa12c 100644
--- a/samples/analytics/sample_utils.py
+++ b/samples/analytics/sample_utils.py
@@ -40,6 +40,7 @@
 import gflags
 import httplib2
 from oauth2client.client import flow_from_clientsecrets
+from oauth2client.client import OOB_CALLBACK_URN
 from oauth2client.file import Storage
 from oauth2client.tools import run
 
@@ -70,6 +71,7 @@
 # Set up a Flow object to be used if we need to authenticate.
 FLOW = flow_from_clientsecrets(CLIENT_SECRETS,
     scope='https://www.googleapis.com/auth/analytics.readonly',
+    redirect_uri=OOB_CALLBACK_URN,
     message=MISSING_CLIENT_SECRETS_MESSAGE)
 
 # The gflags module makes defining command-line options easy for applications.