Add support for registration codes.

BUG=chrome-os-partner:11912
TEST=registration_codes_unittest.py, manual end-to-end test

Change-Id: Ib5729a44952439e90a0d79e1d87484e5593a9ed3
Reviewed-on: https://gerrit.chromium.org/gerrit/28683
Tested-by: Jon Salz <jsalz@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Commit-Ready: Jon Salz <jsalz@chromium.org>
4 files changed