Effect: Added Fatal Poison effect

This is identical to normal Poison, except that it kills the victim. Parrots receive this effect when they are fed cookies.

src/pocketmine/resources/effects.json

@@ -131,5 +131,11 @@
         "id": 24,
         "color": "#FFCEFFFF",
         "name": "levitation"
+    },
+    "fatal_poison": {
+        "id": 25,
+        "color": "#FF4E9331",
+        "name": "poison",
+        "isBad": true
     }
 }