Suppress warnings user can't fix

Requests/urllib3 started issuing warnings about certificates and SSL
that our users are unable to do anything about.  This is a very blunt
way to suppress these warnings unless --verbose or --debug is
supplied on the command line.

Being more precise in the suppression requires importing the warning
classes from urllib3 and dealing with the platforms where it has
been unvendored from requests.  Maybe in the future if there are
concerns that this mutes too much otherwise.

Change-Id: I50bb10a16222de12c5b95bfe042b92e43ea8ee7c

Author: Dean Troyer

openstackclient/shell.py

@@ -1,4 +1,5 @@
 #   Copyright 2012-2013 OpenStack Foundation
+#   Copyright 2015 Dean Troyer
 #
 #   Licensed under the Apache License, Version 2.0 (the "License"); you may
 #   not use this file except in compliance with the License. You may obtain
@@ -19,6 +20,7 @@
 import logging
 import sys
 import traceback
+import warnings
 
 from cliff import app
 from cliff import command
@@ -139,12 +141,15 @@ def configure_logging(self):
         if self.options.verbose_level == 0:
             # --quiet
             root_logger.setLevel(logging.ERROR)
+            warnings.simplefilter("ignore")
         elif self.options.verbose_level == 1:
             # This is the default case, no --debug, --verbose or --quiet
             root_logger.setLevel(logging.WARNING)
+            warnings.simplefilter("ignore")
         elif self.options.verbose_level == 2:
             # One --verbose
             root_logger.setLevel(logging.INFO)
+            warnings.simplefilter("once")
         elif self.options.verbose_level >= 3:
             # Two or more --verbose
             root_logger.setLevel(logging.DEBUG)