Jira/qd 50

https://bugs.indeed.com/browse/QD-50
- Merge the 2 commits from https://github.com/Supervisor/supervisor/pull/292
- Merge the 2 commits from https://github.com/lukeweber/supervisor/commit/04d47d019198287af4c4f09bc201b52dd1a149cf
- switch error output to go to stderr