Merge pull request #161 from hintjens/master

Problem: dangling use of 'dictionary' in scripts
Updated zproto_example.bnf
Added goczmq package support in go codec
Merge pull request #162 from armen/goczmq

Added goczmq package support in go codec
More descriptive error message for invalid signature
Merge pull request #163 from armen/desc-error-msg

More descriptive error message for invalid signature
Problem: Client blocks on destroy if no messages pending on dealer
Solution: return -1 to interrupt zloop on $TERM
Problem: Some branches of s_client_handle_cmdpipe leak memory
Solution: Always free the method string, even on terminate
Merge pull request #164 from jemc/master

Problem: Client blocks on destroy if no messages pending on dealer
Problem: inelegant exit code in cmdpipe handler

Solution: simplify this.