Fix wrong GLTriangleMesh buffer reserve size.
Create OpenGL Qube Mesh Object.
Refactoring Application class.
Refactoring ApplicationRender class.
& Remove test sample mesh object.
Refactoring SDLContext class.
Change Default clear color: Dim Gray(#696969).
Removed for refactoring.
Refactoring OpenGL 3.1 Rendering logic.
Create OpenGL 3.1 Mesh class.
Download GLM library.