This uses mawk's extensions `-W interactive` and `delete array`; it will probably work with certain other AWK implementations as well, but for now it depends on mawk explicitly.

Since all input is run through url-normalise before processing and all output of website and social media extraction is also normalised, it's not necessary to re-normalise again at the end.

Consolidate social media profile, YouTube, and (new) generic web page URL normalisation into one script

Leftover from debugging