Add a convenience method to get mode + nickname.

Use this in the new formatter to avoid having object hashcodes
all over the damn place.

res/com/dmdirc/ui/messages/format.yml

@@ -1,24 +1,24 @@
 ---
 ChannelModeNoticeEvent:
-  format: "-{{client}}:{{prefix}}{{channel.name}}- {{message}}"
+  format: "-{{client.modePrefixedNickname}}:{{prefix}}{{channel.name}}- {{message}}"
   colour: 5
 ChannelNoticeEvent:
-  format: "-{{client}}:{{channel.name}}- {{message}}"
+  format: "-{{client.modePrefixedNickname}}:{{channel.name}}- {{message}}"
   colour: 5
 ChannelMessageEvent:
-  format: "<{{client}}> {{message}}"
+  format: "<{{client.modePrefixedNickname}}> {{message}}"
 ChannelActionEvent:
-  format: "* {{client}} {{message}}"
+  format: "* {{client.modePrefixedNickname}} {{message}}"
   colour: 6
 ChannelSelfMessageEvent:
-  format: "<{{client}}> {{message}}"
+  format: "<{{client.modePrefixedNickname}}> {{message}}"
 ChannelSelfActionEvent:
-  format: "* {{client}} {{message}}"
+  format: "* {{client.modePrefixedNickname}} {{message}}"
   colour: 6
 ChannelSelfExternalMessageEvent:
-  format: "<{{client}}> {{message}}"
+  format: "<{{client.modePrefixedNickname}}> {{message}}"
 ChannelSelfExternalActionEvent:
-  format: "* {{client}} {{message}}"
+  format: "* {{client.modePrefixedNickname}} {{message}}"
   colour: 6
 
 # TODO:

src/com/dmdirc/ChannelClient.java

@@ -75,6 +75,11 @@ public class ChannelClient implements GroupChatUser {
         return getUser().getNickname();
     }
 
+    @Override
+    public String getModePrefixedNickname() {
+        return getImportantMode() + getNickname();
+    }
+
     @Override
     public Optional<String> getUsername() {
         return getUser().getUsername();

src/com/dmdirc/interfaces/GroupChatUser.java

@@ -49,8 +49,8 @@ public interface GroupChatUser {
     GroupChat getGroupChat();
 
     /**
-     * Returns the most important mode that the client holds in its textual
-     * form (e.g. o, v, etc)
+     * Returns the most important mode that the client holds in its prefix
+     * form (e.g. @, +, etc)
      *
      * @return The most important mode the client holds, or an empty string
      */
@@ -71,6 +71,14 @@ public interface GroupChatUser {
      */
     String getNickname();
 
+    /**
+     * Retrieves the nickname or display name used by this client, with their most important mode
+     * prefixed.
+     *
+     * @return This client's nickname with their important mode prefixed (if any).
+     */
+    String getModePrefixedNickname();
+
     /**
      * Retrieves the username or ident used by this client.
      *