Update some URLs

Update some URLs

This mostly changes http: to https: in URLs.  It also updates
some URLs that have moved, removes some URLs that no longer
work, recommends against using procmail (procmail.org no
longer works), and removes some mentions of the
no-longer-existing Gmane, LPF and VTW.
It doesn't update all URLs, just the ones I had time for.
* GNUmakefile (help):
* admin/admin.el (manual-doctype-string):
* admin/charsets/Makefile.in (${charsetdir}/ALTERNATIVNYJ.map):
* admin/charsets/mapconv:
* lisp/net/soap-client.el (soap-create-envelope):
* lisp/org/org.el (org-doi-server-url):
* lisp/textmodes/bibtex.el (bibtex-generate-url-list):
Prefer https: to http: un URLs.