A spurious char got into the previous commit
Fixed issues with grabbing stdout / stderr

- Don't hijack stdout and stderr completely. Instead, push messages to the log flow and make sure they still go to their original destination. This, in particular, fixes #104.
- Properly stop grabbing console when no logger wants them
- Fixed various concurrency issues
- Split messages into multiple log messages based on \n
- Console logs are now separately tagged 'stdout' and 'stderr' in the log flow
Updated iOS tester with additional options