Deal with duplicate files last when combining folders [$10]

Wouldn't be better to deal first? On file copy/move first check for duplicates, then proceed. If I have 16GB collection, and the existing (older) file is 8GB, when I return from what else I'm doing I have to wait a fair amount of time to replace that file. From user convenience would be better to deal with potentially long task at the beginning, from performance point of view - at the end (no need to do checking ahead of time)

Arvigeus: That would mean files had to check every file in advance before even starting copying, thus increasing copy time for all cases (even if there are no conflicts)

Related? https://bugzilla.gnome.org/show_bug.cgi?id=740592

It seems like it would be mega-smart to do something like this:

- If the filename to copy already exists, create a "dummy" file instead.
- If there is atleast 1 dummy files on the drive, but the drive is nearly full (say 5% left), stop creating dummy files, *unless* the rest of the files *can still fit* on the drive.

For every dummy file:
- If the user wants to keep the original file, then delete the dummy file.
- If the user wants to overwrite the original file, delete the original, then rename the dummy file to correct filename.

The dialog for "keep" or "overwrite" is presented at the end, in this way all data has been copied, however, when the user decides what he/she would like to do, it requires much quicker operations: delete and/or rename, to complete the task.

Also, if dummy files are stop being created due to space limitations, then just copy what doesn't conflict.

When dummy files/original files are being removed, start creating the dummy files that should have been created while conflicting files are resolved. Ask the user to resolve those conflicts last.