Moving namespace so it's more discoverable

UseSubscriptionService should be discoverable.
Fixing spelling of Obsolete message

Fixes #187
Test RabbitMQ Control Bus Bug

Adding test to illustrate issue with RabbitMQ Control Bus subcriptions
Passing Subscription Address into Binder

At the moment the Binder assumes the subscription is on the data bus,
but could be on the control bus.
Using Newtonsoft directly now.
Updated build with NuGet updates
Updated Json serialization to support settings configuration
Allow setting own SupportedMessageSerializer

Allow setting a user defined instance of SupportedMessageSerializer at
service bus configuration time. The purpose of this change is to allow
specifying exactly which serializers are supported at message reception.
Allow setting own SupportedMessageSerializer 2

Added missing files for previous commit
PSKESerializer SetContentType fix

Fixed an issue with regards to the
PreSharedKeyEncryptedMessageSerializer and MassTransit 2.7.4 which now
supports multiple serializers at Endpoint.Receive. The content type of
the serialized message was set to that of the wrapped serializer instead
of the encrypted serializer which ultimately caused a serialization
exception at the receiving endpoint. By setting the content type after
the wrapped serializer we now guarantee that the correct serializer is
selected.