As described in #1622, it seems that imp.find_module() on Python 3.2 imports other modules, like io, while running. We don't want deepreload to catch those, so this restores the original import hook for find_module.
It's not terribly neat, but I don't currently see a better way of doing it. Ideally, we'd just delay installing our __import__ until after find_module had run, but our implementation of __import__ can itself call find_module, so this little dance seems to be necessary.
Closes gh-1622, and hopefully fixes a test failure we saw last night.
Fix deepreload on Python 3.
Great, thanks! Looks clean, merging now. And yet again, the Panda shines and caught this! I'm really happy that you set that up, we're reaping the benefits every day.