implement sunrise and sunset, improve sky coloring, implement alpha channel in Tessellator, update threejs

src/js/net/minecraft/util/Vector4.js

@@ -0,0 +1,14 @@
+export default class Vector4 {
+
+    constructor(x = 0, y = 0, z = 0, w = 0) {
+        this.x = x;
+        this.y = y;
+        this.z = z;
+        this.w = w;
+    }
+
+    addVector(x, y, z, w) {
+        return new Vector4(this.x + x, this.y + y, this.z + z, this.w + w);
+    }
+
+}