AsdfFile.info loads array data

[braingram]

It appears that this line is triggering array data to be loaded for every array displayed in the the info:

asdf/asdf/_node_info.py

Line 202 in e86f69a

return hasattr(node, "__asdf_traverse__")

Here is a minimal script showing that info loads array data:

import asdf
import numpy as np

fn = 'test.asdf'
tree = dict([(k, np.arange(ord(k))) for k in 'abc'])
asdf.AsdfFile(tree).write_to(fn)

with asdf.open(fn) as af:
    assert 'unloaded' in str(af['b'])
    af.info()
    assert 'unloaded' not in str(af['b'])