title: Is there a library to support autovivification on Javascript objects?
body: <p>Is there anyway, either natively or through a library, to use autovivification on Javascript objects?</p>
  
  <p>IE, assuming <code>foo</code> is an object with no properties, being able to just do <code>foo.bar.baz = 5</code> rather than needing <code>foo.bar = {}; foo.bar.baz = 5</code>.</p>