implement bounding box 3d (NOT tested)
format GB_Mesh.h
add getter & setter to GB_Mesh.h
format GB_Material.h
add todo to GB_Texture.h
remove unnecessary files
added bounding box 3d, now working
GB_Model now renders bounding box when BB3D_SHOW is true
new TODO in GB_Mesh
now includes GB_BB3D class
GBTA bb is working; issue with outline color of bb