Problem: zproto changes broke hydra

Solution: add models to project.xml, and then fix up hydra_server
to handle new codec API properly.

NOTE: still doens't compile, have to fix zproto_client_c first.
Problem: hydra client was broken

Solution: fixed using latest zproto.
Merge pull request #30 from hintjens/master

Problem: zproto changes broke hydra