rclone library users might be intrested in changing default value to
other, or even disabling it. With current version it's impossible which
leads to races when number of uploaded objects exceeds default limit.
Fixes#3732
For few commands, RClone counts a error multiple times. This was fixed by
creating a new error type which keeps a flag to remember if the error has
already been counted or not. The CountError function now wraps the original
error eith the above new error type and returns it.
This was broken in e337cae0c5 when we deleted the transfers
immediately.
This is fixed by keeping a merged slice of time ranges of completed
transfers and adding those to the current transfers.
This is done to make clear ownership over accounting object and prepare
for removing global stats object.
Stats elapsed time calculation has been altered to account for actual
transfer time instead of stats creation time.