Our recent Gerrit upgrade has made the emails method of the REST API
require essentially administrator permissions, making it no longer
feasible to find secondary addresses for change owners. Secondary
addresses really only served minor uses in this library anyway,
helping identify redundant accounts (which new Gerrit is forcing us
to clean up) and allowing slightly looser association to foundation
profiles.
Drop our use of the emails method, relying instead on the preferred
address provided with the owner record. In rare cases where an
account lacks a preferred address, substitute the committer address
from the first revision of the change where we initially encounter
that user.
Change-Id: Iee58c38a728343776354260c8b2d3fad09633ffa
cfd2cd6a94