Add to bibliography update a check of every URL if broken vs. accessible.#337

MattHeffron wants to merge 2 commits into

mainInterlisp/Interlisp.github.io:mainfrom

mth74--Add_check_if_URL_is_brokenInterlisp/Interlisp.github.io:mth74--Add_check_if_URL_is_brokenCopy head branch name to clipboard