Implemented new Plugin Message API - see http://dinnerbone.com/blog/2012/01/13/minecraft-plugin-channels-messaging/

src/main/java/org/bukkit/plugin/messaging/PluginMessageRecipient.java

@@ -0,0 +1,32 @@
+package org.bukkit.plugin.messaging;
+
+import java.util.Set;
+import org.bukkit.plugin.Plugin;
+
+/**
+ * Represents a possible recipient for a Plugin Message.
+ */
+public interface PluginMessageRecipient {
+    /**
+     * Sends this recipient a Plugin Message on the specified outgoing channel.
+     * <p>
+     * The message may not be larger than {@link Messenger#MAX_MESSAGE_SIZE} bytes, and the plugin must be registered to send
+     * messages on the specified channel.
+     *
+     * @param source The plugin that sent this message.
+     * @param channel The channel to send this message on.
+     * @param message The raw message to send.
+     * @throws IllegalArgumentException Thrown if the source plugin is disabled.
+     * @throws IllegalArgumentException Thrown if source, channel or message is null.
+     * @throws MessageTooLargeException Thrown if the message is too big.
+     * @throws ChannelNotRegisteredException Thrown if the channel is not registered for this plugin.
+     */
+    public void sendPluginMessage(Plugin source, String channel, byte[] message);
+
+    /**
+     * Gets a set containing all the Plugin Channels that this client is listening on.
+     *
+     * @return Set containing all the channels that this client may accept.
+     */
+    public Set<String> getListeningPluginChannels();
+}