Add clan ranks to clan chat

- Extend API to include support for getting clan members and
informations about them
- Add API for manipulation with modIcons
- Display clan ranks in clan chat (add to ClanChat plugin)
- Add new hook for clan members changed

Signed-off-by: Tomas Slusny <slusnucky@gmail.com>

runelite-client/src/main/java/net/runelite/client/callback/Hooks.java

@@ -157,6 +157,12 @@ public class Hooks
 				eventBus.post(varbitChanged);
 				break;
 			}
+			case "clanMembersChanged":
+			{
+				ClanMembersChanged clanMembersChanged = new ClanMembersChanged();
+				eventBus.post(clanMembersChanged);
+				break;
+			}
 			case "resizeChanged":
 			{
 				//maybe couple with varbitChanged. resizeable may not be a varbit but it would fit with the other client settings.