This assertion got triggered in a number of harmless situations and it's not always easy to avoid. Trying to avoid it, it has already caused a rather bad task starvation bug (#1441), so at this point it seems to be better to get rid of it.
See also #1407
(cherry picked from commit 621e34b388848c762a7525149ea449ad082996a1)
The previous fix for #1376 resulted in a possible task starvation when the peer reset the connection before the outbound buffer was drained. The new approach now always resumes the waiting task exactly once, no matter how many events happen and no matter in which order.
(cherry picked from commit 350130a2b05cfbf12764ffaa6a86403eacf172d9)
The library is able to support simple TCP servers in the current state. The API is still mostly compatible with mainline vibe.d, but the driver systen has been replaced by the eventcore library and sockets/files/timers/... are now structs with automatic reference counting instead of GC collected classes. The stream interfaces have been removed for now.
