Merge pull request #36 from hintjens/master

Updates to C4.1
Merge pull request #37 from hintjens/master

Removed redundant Changes section
Merge pull request #38 from hintjens/master

Removed redundant references section
Merge pull request #39 from hintjens/master

Updates to FILEMQ and ZRE
Merge pull request #40 from hintjens/master

Fixed version number of ZMTP v3.1
Fixed missing longstr in grammar