Drop support for botan < 2.0

fix #3274

Make botan’s policy configurable from a file

fix #3244

Refactoring louloulibs and cmake

Use OBJECT libraries
Remove the louloulibs directory
Write FOUND variables in the cache

Pass the shared_ptr by reference, to avoid useless copies

Do not require revocation info for a certificate to be valid

If anyone has any reason to believe this is a bad idea, please let me know.

Don’t use global static members but functions that return a reference to an internal static object

See https://github.com/randombit/botan/issues/761

Update the verify_certificate_chain code to work with botan >= 1.11.34 as well

Add a missing ifdef botan

Add some missing botan includes

Clean a few more things

Use the new botan 1.11.32 Tls::Client API (but stay compatible with older ones)

TLS: Enable ecc point compression

If available in Botan.

There is an issue where, if botan supports it but we don’t enable it, then
the TLS handshake may fail with some servers

move is_connecting outside of an ifdef

Remove some useless virtual method from SocketHandler

Move all the connect() logic from TCPSocketHandler into a subclass

This way, TCPSocketHandler only deal with the message sending/receiving, not
the connect() or anything else.  This will be used for implementing servers
(because when a client is accepted, we don’t need all the connect() and dns
resolution stuff).

Add a missing <chrono> include

Add get-irc-connection-info adhoc command

fix #3171

Directly use Botan::byte instead of char, to avoid an unnecessary cast

Replace all include guards by #pragma once

It’s $CURRENT_YEAR

Add a missing vector include