Don't need 2to3 instances fixer now.

$ 2to3 --no-diffs -n -w -f isinstance -d Bio BioSQL Tests Doc Scripts
RefactoringTool: No files need to be modified.

$ 2to3 --no-diffs -n -w -f isinstance Bio BioSQL Tests Doc Scripts
...
(makes no changes, seems to consider it for a few files - odd)