Postpone file operation dialogs that require user decision

[gotar]

During many operations some dialogs might pop up asking user to make a choice (like overwriting file, ignoring some warnings e.g. chmods on vfat partitions etc.). Some of them make sense to suspend operation ('insufficient space' requires to free some before proceeding), while other might wait till end (overwriting or not particular file is independent on proceeding with all the others).
Of course in some situations user may want to abort entire operation on first pop up (indicating some kind of error), so such postponing must be optional.
It would be especially useful for time-consuming operations, as now it happens that after an hour user notices, that since last 55 minutes nothing was done because waiting for his input.

I'd suggest adding separate button for this:

[< OK >] [Best effort] [ Background ] [ Cancel ]

[andrew_b]

Ticket #3206 has been marked as a duplicate of this ticket.