More work to drivers

- Add gfx_test
- add texture loading to GfxOpenGL
- add full submit code
- add debug logging
- add construct and destroy functionality to Pool
- add command functionality
- add vertex and index pools to lithium (static and not threadsafe yet)
- Update GfxDriver Matrix with SetViewPort
- Add glfw (only dependency of gfx_test) maybe later required for input driver

source/common.cpp

@@ -0,0 +1,6 @@
+#include <iostream>
+#include <pd/common.hpp>
+
+void PD::Log(const std::string& txt) {
+  std::cout << "[PD] " << txt << std::endl;
+}