Many javadoc fixes thanks to Celtic Minstrel

src/main/java/org/bukkit/command/PluginCommand.java

@@ -24,6 +24,7 @@ public final class PluginCommand extends Command {
      * @param args All arguments passed to the command, split via ' '
      * @return true if the command was successful, otherwise false
      */
+    @Override
     public boolean execute(CommandSender sender, String commandLabel, String[] args) {
         boolean success = false;