Accessor type mismatch

In file IOglTF.h in function

```
template<class T>
/*static*/ const utility::char_t *IOglTF::accessorType (int size, int dim)
```

there is an error in line _194_, there should be _szIVEC4_ instead of _szIVEC2_.

```
case 4: return (type == FLOAT ? szVEC4 : (type == INT ? szIVEC4 : szBVEC4)) ;
```
