Comment 9 for bug 462891

Added a LP Foundations task as well. Branch lp:~danilo/launchpad/bug-462891 provides a generic implementation of preferredemail which also reads from the auth store (at least I've been led to believe it does).

The branch that landed for translations (lp:~danilo/launchpad/bug-462891-none) only works around the problem by not displaying an email address if it's None.