better editing of the split list

[srkline]

the edit and use of the "SplitFileWave?" is rather awkward. it is set to the names of the split files at the time they are split. It is used when the files are read back in for decimation. BUT it is also used when the EDITED files are read back in for accumulation -- and these are NOT the same files and not even the same TYPE of files. And there is no logical way to edit these waves, pickup the file names automatically, etc. but it rather depends on the user having good working knowledge of Igor.

This needs a better solution.