environ: make less "underline" also be italic

It'd be nice if Arch's less and/or ncurses understood real italics,
the way Debian currently does (I think they have "5.9+20140913-1"
whatever that might mean). For now use this.
environ: change 'us'/'ue' to italic-only
bashrc: "temporarily" disable bash-completion
bash/aliases: scrape-reddit: accept multiple URLs
mailcap: render message/disposition-notification