Add info about the sweet REPL in the README

Describe how you use the REPL, how to change the path of the socket,
and lists commands you can use in the REPL
Allow timeouts to be configurable

add additional options to clusterMaster config

* `stopTimeout` - Time in milliseconds to wait for worker to stop before
  forcefully killing the process during restart or resize, default 5000
  (5 seconds)
* `skepticTimeout` - Time in milliseconds to wait for worker to live
  before shutting previous worker down during restart, default 2000
  (2 seconds)
emit events on resize, restart, quit, quitHard

Return emitter from clusterMaster constructor.

Also provide getter clusterMaster.emitter() which returns the
same emitter.

Emit events when clusterMaster methods (resize, restart, quit,
or quitHard) are invoked.

The event is emitted to allow additional cleanup in your code
on the tick prior to the method being invoked.

```javascript
// listen to events to additional cleanup or shutdown
clusterMaster.emitter()
  .on('resize', function (clusterSize) { })
  .on('restart', function () { })
  .on('quit', function () { })
  .on('quitHard', function () { });
```
export debug

Export debug() so server can write debug output to both stdout and
any REPL's.
Merge branch 'emitEvents' into 0.0.10-rev1
Merge branch 'exportDebug' into 0.0.10-rev1

Conflicts:
	cluster-master.js
add nc as possible client
add help to REPL and update README
make REPL location configurable with options

Allow `repl` config option passed into clusterMaster constructor

* `repl` - where to have REPL listen, defaults to `env.CLUSTER_MASTER_REPL` || 'cluster-master-socket'
  * if `repl` is null or false - REPL is disabled and will not be started
  * if `repl` is string path - REPL will listen on unix domain socket to this path
  * if `repl` is an integer port - REPL will listen on TCP 0.0.0.0:port
  * if `repl` is an object with `address` and `port`, then REPL will listen on TCP address:PORT
provide repl config examples
Merge branch 'configREPL' into b0.0.10-rev1-withConfig

Conflicts:
	README.md
change REPL quit to stop

Since quit is a common command to exit certain
types of command shells, I felt it would be better
to use a different name for stopping the cluster,
since it would be easy to get confused and accidentally
shut down the cluster when simply wanting to exit the
REPL shell.

I switched the REPL command to stop() for a graceful
shutdown and a kill() for stopping hard.
Merge branch 'configREPL' into b0.0.10-rev1

Conflicts:
	cluster-master.js
restart event have workers param and add restartComplete
Merge branch 'emitEvents' into b0.0.10-rev1
if already restarting still call cb
revert previous commit

should not call cb in case of error
the restart cb is only called on success
Merge branch 'emitEvents' into b0.0.10-rev1