Use dictionary format from zproto
Added SEND and RECV events

- to ZRE_LOG protocol
- to allow tracing of message i/o activity
New draft version of ZRE protocol

- matching changes in 'strings' and 'dictionary' types
- tracking work done in zproto codec generator
- implemented in zyre master, aiming for Zyre v1.0 release
Added deprecated-by note
Fixed deprecated-by note