Merge pull request #3 from amyangfei/develop

Add a basic protocol doc; change several comments.
remove unused function in dzbroker.c; change 2 inner function to static

remove client_task and worker_task;
change clent_task_mdp and worker_task_mdp to static.
remove unused source file

remove test_client.c, test_worker.c and mdp_broker.c
test branch add submodule of hired is
minor change for log switch
change cloudfe, statebe binding to tcp endpoint; add some other featrue

simple sleep function; simple node endpoint config file
move broker test simulating code to dztester.c
some testing code