alias: allow reference through 's#' We keep the 't#' option, but we hope to be able to deprecate it at some point. We move to 's#' because it refers to `stack` a more generic concept. than topic. In addition, this allows to phase out 'b#' that collide with normal hex-node.

test-drop.t
test-inhibit.t
test-simple4server.t
tests/test-simple4server-bundle2.t