provide opt-out from security.ssl.require_safe_negotiation=true ?
Should we provide an opt-out option for poor yahoo  (and potentially others) users? (This might be anyway a requirement for a successfull AMO review...)
Also: Is yahoo the only one (throughout the big freemailers) that doesn't support secure reneg.? What is currently the overall situation? How many freemailers/users are we excluding with this setting ?
 https://lists.torproject.org/pipermail/tor-talk/2012-August/025411.html  https://github.com/ioerror/torbirdy/blob/master/components/torbirdy.js#L127 https://wiki.mozilla.org/Security:Renegotiation#security.ssl.require_safe_negotiation