Modify cros_build_lib printing commands to use logging commands.

We did a lot of work to re-create logging funcitonality in cros_build_lib.
This change modifies the underlying implementation of our implementation
to use logging.

This immediately gives us timestamps per logged command which is extremely
useful when diagnosing timing regressions and seeing when got done when.

I've also cleaned up old logging code in other modules and cleaned up some
pylint issues found in cros_build_lib.py

BUG=chromium-os:20723, chromium-os:30327
TEST=pylint, unittest, local buildbot, remote trybot.

Change-Id: I65a5289243b85d739d436cbaa274285aff9dff7d
Reviewed-on: https://gerrit.chromium.org/gerrit/21581
Commit-Ready: Chris Sosa <sosa@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
Tested-by: Chris Sosa <sosa@chromium.org>
diff --git a/scripts/cbuildbot.py b/scripts/cbuildbot.py
index 9f1ba17..feb472e 100644
--- a/scripts/cbuildbot.py
+++ b/scripts/cbuildbot.py
@@ -12,6 +12,7 @@
 
 import distutils.version
 import glob
+import logging
 import multiprocessing
 import optparse
 import os
@@ -1010,7 +1011,7 @@
   _PostParseCheck(options, args)
 
   if options.remote:
-    cros_lib.DebugLevel.SetDebugLevel(cros_lib.DebugLevel.WARNING)
+    cros_lib.logger.setLevel(logging.WARNING)
 
     # Verify configs are valid.
     for bot in args: