prompt: adds 'version' command

prompt/prompt.go

@@ -176,6 +176,8 @@ func (p *Prompt) StartInteractive() error {
 			}
 
 			p.receiveMessage(args[1], body)
+		case line == "version": // Version
+			fmt.Printf("Server version: %s\n", p.server.Version())
 		case line == "help": // Help
 			fmt.Println("Usage: <command> [args]")
 			fmt.Println("Where <guid> is specified, '*' can be provided as a wildcard.")
@@ -185,6 +187,7 @@ func (p *Prompt) StartInteractive() error {
 			fmt.Println("\tls <guid>         list messages for conversation")
 			fmt.Println("\tmark [-r] <guid>  mark conversation as unread/[r]ead")
 			fmt.Println("\trecv <guid> <msg> receive a message")
+			fmt.Println("\tversion           print server version")
 			fmt.Println("\thelp              show this help")
 			fmt.Println("\texit              exits the program")