If I have the preference "updateSavesFiles" on, then the updates are saved into a folder called "updates".  If I update from an older image, and have the preference on, I'd like it to load them from the local disk first, and only go out to the net if the update isn't available locally.  This allows me to cache updates, and install them faster.

I can do this manually with "Utilities applyUpdatesFromDisk", but would like to use the preference to enable it.  Does anybody see any problems with this?  There's a potential security risk, but not much more likely than inserted bogus updates at the server end.

And having done this, would it make sense to always look for local updates first, so that reloading from a clean image doesn't require changes the preferences first?  Although with Ned's changes to save/load preferences from disk, it's not much hassle.

I suspect that the code is already in the Utilities class, but I haven't grokked it yet.