Translations:Std AddonMgr/57/en

Note that this code blocks until complete, so you shouldn't run it on the main GUI thread. To the Addon manager, "install" and "update" are the same call: if this addon is already installed, and git is available, it will be updated via "git pull". If it is not installed, or was installed via a non-git installation method, it is downloaded from scratch (using git if available).