Fix Aphlict logging
Summary:
Yeahhhhhhhh....
- Open a "stream", not a "steam".
- Make error easier for users to understand.
- Write to the log in debug mode so the issue is more apparent.
Test Plan:
- Started server with bad permissions, got usable error message.
- Started server with good permissions, got logfile.
Reviewers: joshuaspence, btrahan
Reviewed By: btrahan
Subscribers: Korvin, epriestley
Differential Revision: https://secure.phabricator.com/D11339