Add javax.annotations to the API

Used this set specifically because they are present in NMS already.

Spigot-API-Patches/0023-Use-ASM-for-event-executors.patch

@@ -1,4 +1,4 @@
-From 10a4791de112ae58095cfc6027dc367edd1097a0 Mon Sep 17 00:00:00 2001
+From 26c8d481578cd7a29103c0c3d22939dfd0c85d63 Mon Sep 17 00:00:00 2001
 From: Techcable <Techcable@outlook.com>
 Date: Thu, 3 Mar 2016 13:20:33 -0700
 Subject: [PATCH] Use ASM for event executors.
@@ -6,10 +6,10 @@ Subject: [PATCH] Use ASM for event executors.
 Uses method handles for private or static methods.
 
 diff --git a/pom.xml b/pom.xml
-index 6646f4a..a7f6468 100644
+index f1c9e34..400968f 100644
 --- a/pom.xml
 +++ b/pom.xml
-@@ -126,6 +126,12 @@
+@@ -133,6 +133,12 @@
              <version>1.3</version>
              <scope>test</scope>
          </dependency>
@@ -395,5 +395,5 @@ index d8b9c24..40fd71d 100644
                  eventSet.add(new TimedRegisteredListener(listener, executor, eh.priority(), plugin, eh.ignoreCancelled()));
              } else {
 -- 
-2.9.3
+2.10.0.windows.1