motd: Allow for reading the current motd when no additional args given.

Closes #155, merges #157

Squashed commit of the following:

commit bcb0810637c99223753629a2e55169b07ee9fe51
Author: Andrey Petrov <[email protected]>
Date:   Wed Aug 3 17:58:37 2016 -0400

    motd: Refactor inner conditions

commit ac28c8cb4e8dc2a0d23abe3dcf52b69175cde51b
Author: Aaron <[email protected]>
Date:   Tue Aug 2 09:38:36 2016 +0300

    Fix small issues with the help message

commit a80ae77e1d691a4ec7125be5441d4f6eea767a75
Author: Aaron <[email protected]>
Date:   Tue Aug 2 09:30:21 2016 +0300

    Print the motd if no parameters are passed

commit 2db1b3c123661cdbd622d5ba2ff81ede8cb8a951
Author: Aaron <[email protected]>
Date:   Tue Aug 2 09:29:41 2016 +0300

    Update the motd command's description

host.go

@@ -425,15 +425,21 @@ func (h *Host) InitCommands(c *chat.Commands) {
 	c.Add(chat.Command{
 		Op:         true,
 		Prefix:     "/motd",
-		PrefixHelp: "MESSAGE",
-		Help:       "Set the MESSAGE of the day.",
+		PrefixHelp: "[MESSAGE]",
+		Help:       "Set a new MESSAGE of the day, print the current motd without parameters.",
 		Handler: func(room *chat.Room, msg message.CommandMsg) error {
-			if !room.IsOp(msg.From()) {
-				return errors.New("must be op")
+			args := msg.Args()
+			user := msg.From()
+			motd := h.motd
+
+			if len(args) == 0 {
+				room.Send(message.NewSystemMsg(motd, user))
+				return nil
+			}
+			if !room.IsOp(user) {
+				return errors.New("must be OP to modify the MOTD")
 			}
 
-			motd := ""
-			args := msg.Args()
 			if len(args) > 0 {
 				motd = strings.Join(args, " ")
 			}
@@ -444,7 +450,6 @@ func (h *Host) InitCommands(c *chat.Commands) {
 			if motd != "" {
 				room.Send(message.NewAnnounceMsg(motd))
 			}
-
 			return nil
 		},
 	})

identity.go

@@ -45,6 +45,7 @@ func (i Identity) Whois() string {
 	if i.PublicKey() != nil {
 		fingerprint = sshd.Fingerprint(i.PublicKey())
 	}
+	// TODO: Include time joined, client, etc.
 	return fmt.Sprintf("name: %s"+message.Newline+
 		" > ip: %s"+message.Newline+
 		" > fingerprint: %s", i.Name(), ip, fingerprint)