So that the 500 error view will render properly, even though no variables are
set. We keep the variable static_hidden, which by design is not used on the
500 page.
Fixes#240.
(imported from commit 3c7534f896479b7d7edbe5ef13958481e169a13c)
The key property is that we never reveal the non-public directory name
4nrjx8cwce2bka8r to a not-logged-in user. This makes it less likely that
random people from the Internet will download all our client code while we're
still in private beta.
(imported from commit 7428e847e0a1a34152cb6dc2b677c1b47290c202)
Keegan McAllister