File extension may contain spaces by using gettext_strftime()

Long email addresses in system messages may be folded #502

WWSympa: Loading home page takes long time

WWSympa: Older CSS files would be cleared

Allow to use Gitlab CI

Avoid two-args open and bareword filehandle. Ignore errors.

Fix #301 — Add global mail signature feature

Fixed by preventing folding words matching email regexp.

When user is logged-in, Sympa collects information about membership/adminship among all lists, content of moderation spool and so on, though they will never be used.  Fixed by removing code collectiong information in vain. Deprecated web_tt2/news.tt2.

For those who prefer to work on Gitlab (or use Gitlab CI while using
Github[1]), here's a working .gitlab-ci.yml.

Docker images for the CI are published on
https://framagit.org/luc/DockerFiles/tree/master/sympa-perl

[1] See https://about.gitlab.com/solutions/github/

Fixed by clearing older style.css* and lang.css* under $CSSDIR when they would be updated.

Note: Among files under $CSSDIR, fullPage.css*, print.css* and print-preview.css* will no longer be used nor updated. These may be removed manuallly.

Additional fix for #474.

Prevent warning on undefined salt variable.

Crash in create_list_request when list name is missing #490

Additional changes for #492

Add token to prevent CSRF.

Add a etc/mail_tt2/message.global_footer or
etc/mail_tt2/message.global_footer.mime file and it will be added to all
messages.
Obviously, only admins can edit that file.
It can be used to add an unsubscribe link while letting users add their
own list signature.

(This probably makes responses a bit slower.)

Updating source texts according to fixes on en_US catalog