Sync

#30 #45
storage sync support

It doesn't currently preserve existing settings. The problem there is that I'm not sure of the best place to put that code in sab, and it's not safe/dirty to handle the initial migration in fancy-settings since the passwords need to be stripped out. Didn't need too many changes in sab overall since fancy-settings became synchronous enough. Couple of upgrade things tossed in. I changed the bg page to just a scripts list in the manifest and updated a few messaging calls that were generating errors for being deprecated at some point. Also the obvious new storage permission in the manifest is notable.

todo on this is to add in the listener to auto-update remotes when one of the extensions sets a value on storage.sync but that'll be on the fancy-settings end unless you'd like a message/callback or some such when the occurs.