Dropped stdout logger in favor of /dev/stdout.
Eye-candy codestyle.
Expose app_t::info() via the service.
Fixed a race condition with session choking.

If a slave manages to send the close event before the client closes its
part of the stream, then there's a race condition which sometimes leaves
sessions not closed forever.
Fixed the previous fix.
Use atomics for session operations.
There's no enum specialization for atomic<T>.
Unlock the Locator while querying the gateway.
Dropped an unused include.
Use relaxed memory ordering on session state.
Even more eye-candy!
Drop atomics in favor of simple old mutexes.
Changelog bump - 0.10.5-17.