Rename make_dtype<T>() to ndt::make_type<T>()
Rename array::get_dtype to array::get_type
Rename 'dtypes' directories to 'types'
Rename dtype_properties/functions to type_properties/functions
Rename dtype_assign to typed_data_assign
Rename dtype_promotion to type_promotion
More dtype/type naming cleanup
Rename print_dtype to print_type
Clean up the rest of dtype -> type usage