Release 0.1.0

Bug Fixes:
- Manually implement clone for actor wrappers

Features:
- Drop assumption that events can be encoded
- Basic support for swappable executors
- JoinHandle abstractions
- Immutable references and sync api
- SyncActor
- Add executor to Actor trait signature
- Provide ActorExt::stream
- Add sync version of call and stream
- Add new type macros for Actors
- Add prelude
- Wrapped_event!() macro
- Waiter/Trigger
- Shutdown and Catchup
- Add async_trait and enum_dispatch to prelude
- Adaptor utility type
- Make macros take care of completion token
- Remove directional event
- Remove collector

Refactor:
- Use owned context for AsyncActor
- Remove priority system