Add a source to displayable events.

Need this to figure out where to display them, for now.

src/com/dmdirc/events/ChannelDisplayableEvent.java

 package com.dmdirc.events;
 
 import com.dmdirc.Channel;
+import com.dmdirc.FrameContainer;
 
 import java.util.Optional;
 import java.util.concurrent.atomic.AtomicReference;
         return properties;
     }
 
+    @Override
+    public FrameContainer getSource() {
+        return getChannel();
+    }
+
 }

src/com/dmdirc/events/DisplayableEvent.java

 
 package com.dmdirc.events;
 
+import com.dmdirc.FrameContainer;
+
 import java.util.Optional;
 
 /**
      * @return The timestamp the event occurred at.
      */
     long getTimestamp();
+
+    /**
+     * Gets the source of the displayable event.
+     */
+    FrameContainer getSource();
+
 }

src/com/dmdirc/events/QueryDisplayableEvent.java

 
 package com.dmdirc.events;
 
+import com.dmdirc.FrameContainer;
 import com.dmdirc.Query;
 
 import java.util.Optional;
     public DisplayPropertyMap getDisplayProperties() {
         return properties;
     }
+
+    @Override
+    public FrameContainer getSource() {
+        return getQuery();
+    }
+
 }

src/com/dmdirc/events/ServerDisplayableEvent.java

 
 package com.dmdirc.events;
 
+import com.dmdirc.FrameContainer;
 import com.dmdirc.interfaces.Connection;
 
 import java.util.Optional;
         return properties;
     }
 
+    @Override
+    public FrameContainer getSource() {
+        return getConnection().getWindowModel();
+    }
+
 }

src/com/dmdirc/events/ServerUnknownactionEvent.java

  */
 public class ServerUnknownactionEvent extends ServerDisplayableEvent {
 
-    private final String source;
+    private final String sender;
     private final String target;
     private final String message;
 
     public ServerUnknownactionEvent(final long timestamp, final Connection connection,
-            final String source, final String target, final String message) {
+            final String sender, final String target, final String message) {
         super(timestamp, connection);
-        this.source = source;
+        this.sender = sender;
         this.target = target;
         this.message = message;
     }
 
-    public ServerUnknownactionEvent(final Connection connection, final String source,
+    public ServerUnknownactionEvent(final Connection connection, final String sender,
             final String target, final String message) {
         super(connection);
-        this.source = source;
+        this.sender = sender;
         this.target = target;
         this.message = message;
     }
 
-    public String getSource() {
-        return source;
+    public String getSender() {
+        return sender;
     }
 
     public String getTarget() {

src/com/dmdirc/events/ServerUnknownmessageEvent.java

  */
 public class ServerUnknownmessageEvent extends ServerDisplayableEvent {
 
-    private final String source;
+    private final String sender;
     private final String target;
     private final String message;
 
     public ServerUnknownmessageEvent(final long timestamp, final Connection connection,
-            final String source, final String target, final String message) {
+            final String sender, final String target, final String message) {
         super(timestamp, connection);
-        this.source = source;
+        this.sender = sender;
         this.target = target;
         this.message = message;
     }
 
-    public ServerUnknownmessageEvent(final Connection connection, final String source,
+    public ServerUnknownmessageEvent(final Connection connection, final String sender,
             final String target, final String message) {
         super(connection);
-        this.source = source;
+        this.sender = sender;
         this.target = target;
         this.message = message;
     }
 
-    public String getSource() {
-        return source;
+    public String getSender() {
+        return sender;
     }
 
     public String getTarget() {

src/com/dmdirc/events/ServerUnknownnoticeEvent.java

  */
 public class ServerUnknownnoticeEvent extends ServerDisplayableEvent {
 
-    private final String source;
+    private final String sender;
     private final String target;
     private final String message;
 
     public ServerUnknownnoticeEvent(final long timestamp, final Connection connection,
-            final String source, final String target, final String message) {
+            final String sender, final String target, final String message) {
         super(timestamp, connection);
-        this.source = source;
+        this.sender = sender;
         this.target = target;
         this.message = message;
     }
 
-    public ServerUnknownnoticeEvent(final Connection connection, final String source,
+    public ServerUnknownnoticeEvent(final Connection connection, final String sender,
             final String target, final String message) {
         super(connection);
-        this.source = source;
+        this.sender = sender;
         this.target = target;
         this.message = message;
     }
 
-    public String getSource() {
-        return source;
+    public String getSender() {
+        return sender;
     }
 
     public String getTarget() {