Add events for player changing spectator target (#1498)

* Add events for player changing spectator target

- Add PlayerStartSpectatingEntityEvent
- Add PlayerStopSpectatingEntityEvent

Spigot-API-Patches/0070-Add-PlayerArmorChangeEvent.patch

@@ -1,4 +1,4 @@
-From 4ceb745753f3bb90b932daacc58c3fc104e8a795 Mon Sep 17 00:00:00 2001
+From 418c1570fa8d0784cfaadd1a7070143ef2de5241 Mon Sep 17 00:00:00 2001
 From: pkt77 <parkerkt77@gmail.com>
 Date: Fri, 10 Nov 2017 23:45:59 -0500
 Subject: [PATCH] Add PlayerArmorChangeEvent
@@ -146,5 +146,5 @@ index 00000000..0783ac82
 +    }
 +}
 -- 
-2.18.0
+2.19.1