bug fix in mflistfile when getting dataframes and using the "diff" option - cols were being reset after sorting
bug fix in mflistfile when getting dataframes and using the "diff" option
- cols were being reset after sorting

brclark-usgs/flopy,jentjr/flopy,brclark-usgs/flopy,jentjr/flopy,aleaf/flopy,aleaf/flopy