[Addons] Make it possible to distribute addons in a directory.
[Addons] Make it possible to distribute addons in a directory.

with addons that are large and e.g. use git, it is very inconvenient to
have any files that is outside the addon directory. This patch makes it
possible to create an executable dir that is loaded as an addon.

Stvad/anki,subfusc/anki