Adding a retry and logging utility + appengine backend.
This will be used to monitor and diagnose gsutil failures for nacl + chromeos.

BUG=None
TEST=None

Review URL: http://codereview.chromium.org/3036026

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/command_wrapper/bin@54172 0039d316-1c4b-4281-b951-d872f2087c98