Merge pull request #703 from StreamMeDev/close-doc-update

Added documentation for close callback

Author: 3rd-Eden

doc/ws.md

@@ -66,9 +66,9 @@ If `handleProtocols` is not set then the handshake is accepted regardless the va
 
 If a property is empty then either an offered configuration or a default value is used.
 
-### server.close()
+### server.close([callback])
 
-Close the server and terminate all clients
+Close the server and terminate all clients, calls callback when done with an error if one occured.
 
 ### server.handleUpgrade(request, socket, upgradeHead, callback)