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

.gitmodules

@@ -1,3 +1,6 @@
 [submodule "vendor/stb"]
 	path = vendor/stb
 	url = https://github.com/nothings/stb.git
+[submodule "vendor/glfw"]
+	path = vendor/glfw
+	url = https://github.com/glfw/glfw.git