Validate `ActorRefProvider` type when resolving config

Added `task-dispatcher` to default config
Merge https://github.com/akkadotnet/akka.net into dev
Merge pull request #231 from Horusiath/dev

F# API - changed ActorRef to ICanTell interface for (<!) operator
Merge pull request #232 from rogeralsing/dev

Type validation for configs
Fix issue with PhiAccrualFailureDetector
ActorIdentity isn't handled by AutoReceiveMessage and shouldn't extend AutoReceivedMessage
Merge pull request #238 from smalldave/actoridentitybug

ActorIdentity isn't handled by AutoReceiveMessage
Merge pull request #237 from smalldave/phibug

Fix issue with PhiAccrualFailureDetector
Merge branch 'dev' of https://github.com/akkadotnet/akka.net into dev
* Fix `ActorPath.Equals`, now compares addresses too

* Added `SetReceiveTimeout`
Equals tests for ActorPath
Merge pull request #241 from rogeralsing/dev

ActorPath.Equals fix and SetReceiveTimeout
ReceiveTimeoutSpec done
Merge pull request #243 from rogeralsing/dev

ReceiveTimeoutSpec
squashed from inbox-impl branch