…nel to close when it is finished, and consumer to see the close

…outer goroutine did not wait on all inner goroutines that had a chance to set it, also make sure to check error for context.Canceled appropriately

…l via a method that has an escape hatch; unable to change public Events field without breaking api, though

… when getting buffered (first) error

…ntexts for channel ops, though they are very similar now

…her small changes

Functionally revert slack-go#1170 as drafted approach takes correct path of
closing chan on goroutine producer side

…er and ping time channel. Remove deadman file as it is no longer needed