TODO: timeouts

- bparser sandboxing updated to use stream constructor methods from PR#35
- differentiated request/response/command/error transmission
- updated 002 test case to proof of concept for command and request/response

- deque of sent_requests plus modified binary search to find RID's
- bparser callback only exposes message type
- ::respond method implemented in message type exposed in callback
- message type holds weak_ptr to bparser