am db8e83ec: am d816500c: am 8bec09ee: add \'extras\' mechanism to OTA and signing tools

Merge commit 'db8e83ecee6393f19c1d8adbb2ef3eb08b8e3158'

* commit 'db8e83ecee6393f19c1d8adbb2ef3eb08b8e3158':
  add 'extras' mechanism to OTA and signing tools