Handle CGI SSL detection via HTTPS environment better. Some servers send on/off, 0/1, yes/no, and may be upper or lower case. This fix will handle all of those permutations. It was inspired by the detection done in in some other wsgi python web applications I looked at.

#!/bin/sh

hg init

echo "Is there an error message when trying to diff non-existing files?"
hg diff not found

echo "Is there an error message when trying to add non-existing files?"
hg add not found