Changed rebasing criterion so that it only rebases when there are at least 100 object changes. Avoid rebasing small stores.
Fixed the property change value relationship merge method. It was not properly accounting for removals.
There is some indication that cloud files can still contain multiple events, which should not happen. Added some extra checks, and made the code to remove any old file more robust. When we export, if an old file was there, any new event could be added to it, which should not happen.