Added raw message builder to message upgrading hooks
Merge remote-tracking branch 'origin/master' into Development

Conflicts:
	SystemDotMessaging/Projects/SystemDot.Messaging.Specifications/upgrade_hooks/when_sending_a_message_through_upgrade_hooks.cs
	SystemDotMessaging/Projects/SystemDot.Messaging.Specifications/upgrade_hooks/when_sending_another_message_through_upgrade_hooks.cs