Exim's new bounce text handling, issue #448

Add support for TLSv1.3

doc/Makefile: Fails to build list_config.5 etc. #435

Oracle: Make db_name parameter allow net service name or connection identifier along with SID

Make third person singular pronouns gender neutral

External module required during `make` #434

On mysql & PostgreSQL, undefined db_host is treated as "localhost".

Various places in both documentation and default emails to admins/moderators
use he/him/his to refer to generic users of unknown gender. This commit
changes all generic uses of male pronouns to use singular they/them/their.
It also changes "his/her" to "their", but leaves "he or she" unchanged due
to less trivial conjugation issues.  NEWS, AUTHORS.md, and OChangeLog are
unchanged.

Support for TLSv1.3 (RFC8446) is added for LDAP-related functions.

Note: Actual support needs following components:
  - OpenSSL library 1.1.1 or later
  - IO-Socket-SSL 2.060 or later

Fixed by making Sympa::ListOpt not depending on Sympa::Language.

[-bug] doc/Makefile: Intermediate files list_config.pod etc. won't be cleared and failed to update target files.

Refactoring and repairing login form

CSS cannot be updated if css.tt2 was older than previously generated CSS.

Create ${expldir}/${robot} directory if it does not exists

Oracle: Make db_name parameter allow net service name or (easy) connection identifier along with Oracle SID.
Note: DBD-Oracle 1.70 or better is required. cf. CPAN RT #91775.

Template strings passed to javascript were not escaped

Fixed by escaping them with escape_cstr filter.

Timestamp of css.tt2 is not always increased by new installation.

Support for ARC signatures

Currently, estimated max. size of content is approx. 2000 octets, besides alt_emails attribute. Thus 2000 o is required and more is recommended.
- MySQL & SQLite: "text" type may still be used.
- ODBC: varchar allows 8000 o, sometimes 4000 o: Use "varchar(4000)".
- Oracle: Oracle 7 allows 2000 o and 8 and later allow 4000 o: Use "varchar2(2000)".
- PostgreSQL: Change "varchar()" to a compatible type "text".

- Cookie threw back by clients will no longer be used: Value of cookie will be kept in session store.

It is not obvious that this feature is really used. Maybe deprecated in the future.