updated makefile for supporting different target architectures

use "ARCH=arch_name make"

restructured project folder, implementations and headers together under sources/

sources/GL_STUFF/UTILS/ResourceCache.h

@@ -0,0 +1,21 @@
+#pragma once
+#include <string>
+#include <vector>
+#include <map>
+#include "OnlyOnce.hpp"
+using namespace std;
+
+class ResourceCache {
+
+private:
+	ResourceCache ();
+	map<string, GLuint> images;
+	map<string, GLuint> shaders;
+public:
+	static ResourceCache& get() {
+		static ResourceCache instance;
+		return instance;
+	}
+	GLuint getImage(string path);
+	GLuint getShader(string vertPath, string fragPath);
+};