Revert "Small improvements to zmq_device(3) page"

This reverts commit 96bcc9e6.

doc/zmq_device.txt

@@ -31,13 +31,16 @@ Before calling _zmq_device()_ you must set any socket options, and connect or
 bind both frontend and backend sockets.  The two conventional device models
 are:
 
-* proxy model - accept inward connections to frontend socket (by binding it to
-  an endpoint), and make onward connections through backend socket (connecting
-  to endpoints on other nodes). A proxy device model can fit well into an
-  existing topology.
-* broker model - accept connections on both frontend and backend sockets (by
-  binding both to endpoints).  A broker device model creates a star topology
-  where nodes can come and go at any time.
+*proxy*::
+    bind frontend socket to an endpoint, and connect backend socket to
+    downstream components.  A proxy device model does not require changes to
+    the downstream topology but that topology is static (any changes require
+    reconfiguring the device).
+*broker*::
+    bind frontend socket to one endpoint and bind backend socket to a second
+    endpoint.  Downstream components must now connect into the device.  A
+    broker device model allows a dynamic downstream topology (components can
+    come and go at any time).
 
 _zmq_device()_ runs in the current thread and returns only if/when the current
 context is closed.
@@ -118,21 +121,6 @@ assert (zmq_bind (backend, "tcp://*:5556") == 0);
 zmq_device (ZMQ_QUEUE, frontend, backend);
 ----
 
-.Creating a pubsub proxy
-----
-//  Create frontend and backend sockets
-void *frontend = zmq_socket (context, ZMQ_SUB);
-assert (backend);
-void *backend = zmq_socket (context, ZMQ_PUB);
-assert (frontend);
-//  Connect frontend to publisher
-assert (zmq_bind (frontend, "tcp://192.68.55.112:4444") == 0);
-//  Bind backend to TCP port
-assert (zmq_bind (backend, "tcp://*:5556") == 0);
-//  Start a forwarder device
-zmq_device (ZMQ_FORWARDER, frontend, backend);
-----
-
 
 SEE ALSO
 --------