Add rendering implementation for LWJGL

imgui-binding/src/main/java/imgui/ImVec4.java

@@ -0,0 +1,8 @@
+package imgui;
+
+public class ImVec4 extends ImVec2 {
+    public static ImVec4 TMP = new ImVec4();
+
+    public float z;
+    public float w;
+}