0.003_03	2019-10-23	T. R. Wyant
    Allow prohibit_redirect code to return code ref. This has the effect
    of defering to the returned code. It was implemented because I
    wanted to do a little preproscessing and then pass control to
    ALLOW_REDIRECT_TO_INDEX, but could not find a clean way to make a
    goto() work.

    Add -allow-redirect-to-index to eg/test-pod-links

0.003_02	2019-10-22	T. R. Wyant
    Allow code ref for prohibit_redirect, and provide
    ALLOW_REDIRECT_TO_INDEX. The latter is exportable, and allows URLs
    ending in '/' if the redirection is the same except for the part
    after the last slash.

0.003_01	2019-10-21	T. R. Wyant
    Optionally fail URL links that redirect.

0.003		2019-08-30	T. R. Wyant
    Fix test of link to extant-but-undocumented module. The result now
    contains the failing link and line number, and a passing test for
    the entire file is NOT generated.

0.002		2019-08-04	T. R. Wyant
    Skip URL links with server (5xx) errors.  This is controlled by
    Boolean attribute skip_server_errors, which is true by default.  The
    default behaviour is a change from version 0.001, which generated a
    failed test in this case. The logic (if any) is that status 5xx can
    represent an actual server error rather than an incorrect link.

0.001		2019-07-04	T. R. Wyant
    First production release