Total Commander

I suggest making Files~~CombineFiles... to spawn as a separate thread.
Don't like to sit an wait for TC to finish.

Support split/merge in background - it seems to be easy in realization - just call function in another thread and pass file(s) to it. All code is inside of TC so all should be safe already.

Support!

I often use Combine/Split functions in TC, and it would be very handy if they could be done in the background and I could continue to work with TC doing other things.