Simplify caching of modules from %run-ing scripts....
Simplify caching of modules from %run-ing scripts.
Previously, we cleared and re-used a single FakeModule instance in which to
run cells, and cached copies of the modules' namespaces to prevent them from
being cleared. Now, we cache one FakeModule instance per script file, clearing
it and re-using it if the same script is re-run. This seems more robust.
Closes gh-3547