housecleaning

I'm working through removing all dead code. Here is what I have left. Please help me audit.

[ ] third_party/.../go-log -> go-systemd && third_party//bitbucket.org/kardianos/osext
[ ] third_party/.../go-etcd -- @xiangli-cmu is working on it
[ ] error/ -> ./discovery -- @xiangli-cmu is working on it
[ ] http/ -- needs review (does CORS stuff in for main, could be moved?)
[ ] bench/ -- needs review
[ ] fixtures/ -- needs review
[ ] config/ -- we should be able to move this into etcd/
[ ] pkg/ -- needs review? strings is the only thing left.. we may be able to remove it.