How to package this extension

[Saša Bodiroža]

Additionally, if it needs to be setup for Thunderbird too, just change
the value of MOZ_XPI_MOZILLA_DIRS parameter in debian/rules. This
parameter tells the script where it should install the extensions. In
xpi.mk, which is located in /usr/share/mozilla-devscripts/, it
defaults to firefox and firefox-addons, so we need to add thunderbird:

MOZ_XPI_MOZILLA_DIRS = firefox-addons firefox thunderbird

I hope this helps.

-- 
Best regards,
Saša Bodiroža