core hello world /

Diff from to


 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 client that can publish, subscribe,
   get a dump of the state of the broker, and shut the broker down.
+Plus, the build scripts:
+* `_tags`: which sets up the build options for `ocamlbuild`.
+* ``: For building any target, invoking `ocamlbuild`.
+* ``: builds _all_ the executable targets.  Calls out to
+  ``.
 Setting up the toplevel