WIP (unreleased)

Added debug serialization macro (debug_serialize_msg!) for all sent messages
Support ToMessage in actor-spawn methods - #62
Context::send now sends ToMessage objects and Context::send_message sends Box<Message> - #66
Message support for ActorAddress so they can be shared between actors - #67
Added send/receive macros for internal channel operations
Implemented a heirarchical shutdown system
Added ACK messages for message delivery confirmation
Added ActorSpawnHandle for newly created actors

0.1.2 through 0.2.0

Added support for spawning actors (0.1.2)
Introduced runtime manager and round-robin spawn strategy (0.1.3)
Added configuration support for creating new ActorSystem (0.2.0)
Implemented ActorCell (0.2.0)
Implemented ActorAddress (for local routing only) and address resolution (0.2.0)
Basic message sending (0.2.0)
Pattern matching on received types (by use of Any) added. Uses newly (0.2.0) added Message type (which subsumes prost::Message) to implement as_any(). (0.2.0)
Added busan-derive with support for #[derive(busan::Message)] proc-macro (0.2.0)
Updated hello_world example to use derive macro in build.rs (0.2.0)