core hello world /

Diff from to

 a few operations, including publishing, subscribing, getting a dump of
 the current state of the server, and shutting the server down.
+Guide to the files
+These are listed in rough dependency order.
+* ``: For building any target
+* ``: builds _all_ the executable targets
+* ``: Command-line tool that prints "Hello World!"
+* ``: Some common utilities for setting up Async-RPC clients
+  and servers
+* ``: Async-RPC server for answering "hello" query
+* ``: Async-RPC client fro sending "hello" query
+* ``: Core datastructur of the Async message broker
+* ``: Async-RPC server that handles message broker
+  requests.  Backed by the Directory.
+* ``: Async-RPC client that can publish, subscribe,
+  get a dump of the state of the broker, and shut the broker down.
 Setting up the toplevel