add a new annotation to hide commands from tabcompletion and help (#124)

* add a new annotation to hide commands from tabcompletion and help (implements #123)

* do the annotation lookup once

example/src/main/java/co/aikar/acfexample/ACFExample.java

@@ -44,6 +44,9 @@ public final class ACFExample extends JavaPlugin {
         // 1: Create Command Manager for your respective platform
         commandManager = new BukkitCommandManager(this);
 
+        // optional: enable unstable api to use help
+        commandManager.enableUnstableAPI("help");
+
         // 2: Setup some replacement values that may be used inside of the annotations dynamically.
         commandManager.getCommandReplacements().addReplacements(
                 // key - value

example/src/main/java/co/aikar/acfexample/SomeCommand_ExtraSubs.java

@@ -24,8 +24,11 @@
 package co.aikar.acfexample;
 
 import co.aikar.commands.BaseCommand;
+import co.aikar.commands.CommandHelp;
 import co.aikar.commands.annotation.CommandAlias;
 import co.aikar.commands.annotation.CommandCompletion;
+import co.aikar.commands.annotation.HelpCommand;
+import co.aikar.commands.annotation.Private;
 import co.aikar.commands.annotation.Subcommand;
 import org.bukkit.command.CommandSender;
 
@@ -37,4 +40,15 @@ public class SomeCommand_ExtraSubs extends BaseCommand {
     public void onTestSub2(CommandSender sender, String hi) {
         sender.sendMessage(hi);
     }
+
+    @Private
+    @Subcommand("testsub private")
+    public void privateSub(CommandSender sender){
+        sender.sendMessage("Am a sneaky ninja!");
+    }
+
+    @HelpCommand
+    public void help(CommandSender sender, CommandHelp help){
+        help.showHelp();
+    }
 }