v1.3.7 - Broadcast Performance 2

Summary

After getting some profiling data from the last release we were able to determine that much of the performance hits were caused by frequent calls to the asyncio machinery for waiting on data to drain, specifically ensure_future. Since there wasn't much benefit in waiting for broadcasted messages anyways, we are reverting the async refactor for the broadcast code (but we are still keeping it for everything else). This should make a big difference for performance, hopefully bringing us back to where we were with v1.2.

Pull Requests

• Performance: Don't await broadcasts (#548)