Add switch to OKify to stop copying testref files to file.old

[cdsontag]

@oiintam and I realized (again) this am that the OKify process needlessly copies old testref files to a spot locally on disk.

Since the "old" testref files are already in the repo by that time, we (ETC) don't need copies made of them.

[cdsontag]

CC @cslocum @ariedel

[vglaidler]

Note that we want to do this as a switch, not by simply deleting code, because we want it to still function correctly for the non-repo case.

[cslocum]

I brought this up several years ago and Vicki resisted...