Initial implementation of transport-level-id support for rabbitmq transport.
Merge branch 'rabbitmq-transport-id' of github.com:pruiz/Rebus into pruiz-rabbitmq-transport-id
Added general application of rebus-msg-id to headers on send. Added transfering of rebus-msg-id header to deferred messages. Moved fallback assignement og rebus-msg-header to workers general receive method so it falls back for all transports.
Allowing non-deserializable messages to be handled
Setting the header regardless of ID value. ID couldnt be null at that point anyway.
Updated changelog
Prohibited overwrite of Rebus transport message ID in header.