Also update sys_user language if it was specified through API client_update

See merge request ispconfig/ispconfig3!797

re-creation for dkim keys fails (Fixes #5061)

See merge request ispconfig/ispconfig3!796

Added remote functions config_value_get, config_value_add, config_value_update, config_value_replace and config_value_delete to access the sys_config key / value store in ISPConfig from remote api.

Fix #select_server a that is affected by #sidebar a

See merge request ispconfig/ispconfig3!786

Use Acme v2 if supported

See merge request ispconfig/ispconfig3!787

Update letsencrypt.inc.php as per the discussion at #5030. Already pr'ed and merged in master via !778. Perhaps can be merged with stable too?

Update ispconfig.css to fix #select_server a that is affected by #sidebar a padding of 10px. Already pr'ed and merged in master via ispconfig/ispconfig3!766. Perhaps can be merged with stable too?

Add description text for logging options.

update logrotate

See merge request !784

Stable 3.1

See merge request ispconfig/ispconfig3!783

update_record_permissions() isn't callable via API as it has no session_id in its params

See merge request ispconfig/ispconfig3!780

fixed checkbox in dmarc template

See merge request ispconfig/ispconfig3!781