Merge pull request #282 from noxhoej/master

Use IImmutableSet instead of List in EvenBus to make it thread-safe...
PublishedMessageEvent, DeliveredMessageEvent

Here is an addition to already existed events. For instance it can be
usefull for client-side message tracking.
Bump the version
Merge pull request #284 from Pliner/producer-consumer-events

PublishedMessageEvent, DeliveredMessageEvent
Merge remote-tracking branch 'upstream/master'

Conflicts:
	Source/Version.cs
Use ILRepack to internally merge  System.Collections.Immutable.Net40