cloud sync GUI hang

[Miika Turkia]

The cloud sync (at least when started from File menu) hangs the GUI
for forever. At least with my current 1 bit per minute Internet
connection. I think this is also the initial push to the cloud so
quite a bit of data transfer going on. Anyway, a background thread
would be great for this sync. (I am not sure which setting I have
selected under the preferences for syncing in background, nor whether
changing that would solve the issue.)

miika