Dne 26.8.2015 v 14:12 Alexander
Their FAQ is constantly updated:
I'm not sure if there is a valid practical reason to refuse
submitting the addons that we ship to their signing service or
if it is against our policies; at least
mozilla-https-everywhere has been signed.
Mozilla states that they will be offering an unbranded
binary (en_US only) for development and testing purposes.
For example, I am using "GitHub Extension Installer"  to install
development versions of several other add-ons directly from GH. I am
afraid this won't be possible anymore.