Enable standard logging in os-cloud-config

This review adds --debug and --log-config command line parameters to
utilities currently provided by os-cloud-config. By default (when
both parameters are omitted), logging is printed to stdout with
level INFO.

Change-Id: Ibd2c29e30fb23b080fb385b7c8b3236ccaa55e0e
Merge "Enable standard logging in os-cloud-config"