bug#28159: Updater needs to support HTTP(S) servers

[Hartmut Goebel <h.goebel@crazy-compilers.com>]

Hi,
> I just learned that ftp://ftp.gnu.org will be retired on Nov. 1st, 2017,
> so we’ll have to implement a replacement for the ‘gnu’ updater at least.

By change, also this server provides a `ls-lrRt.txt.gz` file.
Unfurtunaly is as a slightly different (date-) format than the one at
kde.org:

kde:

    drwxr-xr-x   3 ftpadmin packager       6 2000-10-01 14:07 adm


gnu:

    drwxr-xr-x   2 root root      4096 Aug  2  2003 third-party


Also by chance ftp.gnu.org also provides a file `find.txt.gz`, listing
all files, including the full path:

    ./video/Stephen_Fry-Happy_Birthday_GNU-nq_600px_425kbit.ogv
    ./old-gnu/g77/g77-0.5.21.tar.gz
    ./old-gnu/guile
    ./old-gnu/guile/guile-www-1.0.1.tar.gz
    ./old-gnu/guile/guile-1.3.2.tar.gz


> At worst, we’ll parse HTML index files like the one at
> <https://ftp.gnu.org/gnu/guile/>,

This is what Ihis bug is about :-) Please mind the query-parameters one
can pass to apache: <https://ftp.gnu.org/gnu/guile/?F=0> is much more terse.

-- 
Regards
Hartmut Goebel

| Hartmut Goebel          | h.goebel@crazy-compilers.com               |
| www.crazy-compilers.com | compilers which you thought are impossible |