Remvoe texture data from mesh class
add don't show again checkbox to generate 3D coordinate messagebox.
.obj files without UVs
new read() to read obj files
remove debug output.
remove loadObj(), loadAssImp() methods and assimp dependency.
clean up: remaining assimp parts
remove indexVbo() and move its content into read()
remove getSimilarVertexIndex() and move it's content into read()
move shader program parameter from render() to init()
clean up