fix jiak's vclock header decoding for non-binary clientIds (atoms, etc.)
fix jiak's vclock header decoding for non-binary clientIds (atoms, etc.)

second two lines of roundtrip_vclock_test/0 test this

trung/riak-webui,trung/riak-webui,trung/riak-webui,trung/riak-webui,trung/riak-webui,trung/riak-webui,trung/riak-webui,trung/riak-webui