add ebuilds for dev-db/etcd* packages and updates for app-admin/fleet package

This chain is only for line 2.  I'm just pointing out that ``/var/run`` is considered a deprecated directory and ``/var/run/etcd`` shouldn't exist any longer.  We should switch it to the real path ``/run/etcd`` if at all possible since ``/var/run`` is just a symlink to ``/run``.