[Bleeding] Added automatically generated plugin-level sub-indexes to the master help index. Addresses BUKKIT-1180

By: rmichela <deltahat@gmail.com>

paper-api/src/main/java/org/bukkit/command/PluginCommand.java

@@ -5,7 +5,7 @@ import org.bukkit.plugin.Plugin;
 /**
  * Represents a {@link Command} belonging to a plugin
  */
-public final class PluginCommand extends Command {
+public final class PluginCommand extends Command implements PluginIdentifiableCommand {
     private final Plugin owningPlugin;
     private CommandExecutor executor;
 

paper-api/src/main/java/org/bukkit/command/PluginIdentifiableCommand.java

@@ -0,0 +1,18 @@
+package org.bukkit.command;
+
+import org.bukkit.plugin.Plugin;
+
+/**
+ * This interface is used by the help system to group commands into sub-indexes based
+ * on the {@link Plugin} they are a part of. Custom command implementations will need to
+ * implement this interface to have a sub-index automatically generated on the plugin's
+ * behalf.
+ */
+public interface PluginIdentifiableCommand {
+    /**
+     * Gets the owner of this PluginIdentifiableCommand.
+     *
+     * @return Plugin that owns this PluginIdentifiableCommand.
+     */
+    public Plugin getPlugin();
+}

paper-api/src/main/java/org/bukkit/help/HelpMap.java

@@ -1,5 +1,6 @@
 package org.bukkit.help;
 
+import java.util.Collection;
 import java.util.List;
 
 /**
@@ -20,6 +21,13 @@ public interface HelpMap {
      */
     public HelpTopic getHelpTopic(String topicName);
 
+    /**
+     * Returns a collection of all the registered help topics.
+     *
+     * @return All the registered help topics.
+     */
+    public Collection<HelpTopic> getHelpTopics();
+    
     /**
      * Adds a topic to the server's help index.
      *