Add Chat.close() (SMACK-356)

core/src/main/java/org/jivesoftware/smack/Chat.java

@@ -128,6 +128,16 @@ public class Chat {
         listeners.remove(listener);
     }
 
+    /**
+     * Closes the Chat and removes all references to it from the {@link ChatManager}. The chat will
+     * be unusable when this method returns, so it's recommend to drop all references to the
+     * instance right after calling {@link #close()}.
+     */
+    public void close() {
+        chatManager.closeChat(this);
+        listeners.clear();
+    }
+
     /**
      * Returns an unmodifiable collection of all of the listeners registered with this chat.
      *

core/src/main/java/org/jivesoftware/smack/ChatManager.java

@@ -227,6 +227,13 @@ public class ChatManager {
         return chat;
     }
 
+    void closeChat(Chat chat) {
+        threadChats.remove(chat.getThreadID());
+        String userJID = chat.getParticipant();
+        jidChats.remove(userJID);
+        baseJidChats.remove(StringUtils.parseBareAddress(userJID));
+    }
+
     private Chat createChat(Message message) {
         String threadID = message.getThread();
         if(threadID == null) {