Changes

; installAddonFromSyncData(syncData, syncGUID, callbackObj) : Installs an add-on from sync data. Receives the data from the original add-on, the GUID it should be installed with, and an object describing callbacks to be invoked when specific events occurs. The manager will try to obtain an install record and then execute the install. The callbackObj contains the optional keys *onFailure*, *onInstall*, and *onNewSyncGUID* which can be functions that are called when those events occur. Each function receives *syncData* and *syncGUID* as their first arguments. *onInstall* will additionally receive the newly-created (or existing) add-on record and a boolean indicating whether a restart is required. *onNewSyncGUID* will receive as a 3rd parameter the new syncGUID for the already-installed add-on. As inferred from the callback definition, the function must be able to detect existing add-ons from the *syncData* and update the *syncGUID* of that add-on to the value specified.

; uninstallAddonBySyncGUID(syncGUID, callbackObj) : Uninstalls an add-on specified by its syncGUID. The callbackObj has the optional keys *onSuccess* and *onFailure*. Each receives as an argument the passed *syncGUID*.