fix aliasing to a node that does not yet contain children
Adding javadoc annotation for 'fold' query operation.
Merge pull request #22 from stewartoallen/at-pull-002

fix aliasing to a node that does not yet contain children
add support for array returns in element query
[cherry pick commit from stewartoallen a0549909393c8e3206c30becd2bf357adbb97b77]
Promoting VirtualTreeNode class visibility to public.
Cherry pick of stewartoallen 1fdaa14156f33ab9159ca4da1fc670e151169596.
Renaming static inner class from "ITER" to VirtualTreeNodeIterator.