* Change an instance of Firefox to Thunderbird [1]
* Workaround a potential crash with JavaScript pop-ups [2]
* Use Xvfb to initialize the extensions datastore as root
[2] https://bugzilla.mozilla.org/show_bug.cgi?id=264557
Sbumitted by: Radek Kozlowski <radek@raadradd.com> [1]