Syncing large number of items affected by Dropbox rate limiting

[robertknight]

My store now has ~230 items in it and during the initial sync onto a new machine, a few dozen of these typically fail due to hitting Dropbox rate limiting errors. Trying again after a delay of 10-20 seconds, the remaining items then usually sync successfully.

Since the Agile Keychain format uses one file per item and one API call is required to fetch each file, that can result in hundreds of API calls every few seconds.

This issue should be fixed in the cloud keychain format since there are far fewer files in the store (one per unique 2-char UUID prefix), but when syncing with Agile Keychain vaults, it would make sense to do client-site rate limiting of outgoing API calls.