Fetch the credentials contained in the URL from the `Synchronizer` when initializing `StorageSaver`.
The `ResettableTimer` class' code did not account for the `function` attribute to possibly call the timer, creating a deadlock because the lock was already taken while calling the function. Move the function call out of the lock.
Implement the SyncingManager class which wraps the Manager and implements save syncing features, which comprise autosave and saving via synchronizers.