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
Fixed grammar for zproto compatibility
Moved all unimplemented functionality into new RFC

- ZMTP v3.1 is RFC 37
- Allows RFC 23 to be "stable"
- only ERROR reply from authentication is missing in libzmq
Fixed FILEMQ spec for grammar
Merge pull request #39 from hintjens/master

Updates to FILEMQ and ZRE