Add a who type method to GroupChat

src/com/dmdirc/Channel.java

@@ -563,4 +563,9 @@ public class Channel extends FrameContainer implements GroupChat {
         return channelInfo.getMode(mode);
     }
 
+    @Override
+    public void requestUsersInfo() {
+        channelInfo.sendWho();
+    }
+
 }

src/com/dmdirc/events/DisplayProperty.java

@@ -35,7 +35,7 @@ public interface DisplayProperty<T> {
     /** The background colour of text relating to the event. */
     DisplayProperty<Colour> BACKGROUND_COLOUR = new DisplayPropertyImpl<>();
     /** Whether to suppress display of the event. */
-    DisplayProperty<Void> DO_NOT_DISPLAY = new DisplayPropertyImpl<>();
+    DisplayProperty<Boolean> DO_NOT_DISPLAY = new DisplayPropertyImpl<>();
 
     final class DisplayPropertyImpl<T> implements DisplayProperty<T> {}
 

src/com/dmdirc/interfaces/GroupChat.java

@@ -182,4 +182,9 @@ public interface GroupChat extends Chat {
      * @return The current value of the mode.
      */
     String getModeValue(final char mode);
+
+    /**
+     * Requests information about all the {@link User}s in this GroupChat.
+     */
+    void requestUsersInfo();
 }