Description: Added -E option to h5ls. When set, this alows h5ls to enter
external files (currently only through an external link). The -r option by
itself will no longer allow h5ls to traverse external links.
Tested: kagiso, linew, smirom (h5committest)
Description: Adds capability to h5ls to traverse external links when the -r
(recursive) option is given. Changes to the way absolute path names are patched
in h5trav.c. Changes to the way recursive traversal starting from a non-root
group is handled (which also fixes some preexisting issues). Tests added for
these cases.
Tested: kagiso, smirom, linew (h5committest)
