## Description of change
Finally figured out where the deadlock was coming from - it's because
the `dump_to_logger` was writing `SuperstepSound: Audio device is not
available` to the logger which calls back into the log hook, and then
emits another deferred message, trying to acquire the lock again on the
same stack.
## Testing
Tested the superstep sound failure case again.
## Link to GitHub Issue, if one exists
#388
## Description of change
Instead of setting flags in `signal` and logging when we crash, create a
class for logging deferred semi-fatal messages, and dump them to the log
immediately before crashing or shutting down.
## Testing
Tested each failure case by injection.
bicarus-dev