Support of different default pass schemes + support of BLF-CRYPT (#3832)

* Introduce MAILCOW_PASS_SCHEME in order to support blowfish (cf. mailcow/mailcow-dockerized#1019)

* Furthermore added dovecot to support new environment varible for MAILCOW_PASS_SCHEME defaulted to SSHA256

* Revert changes regarding gitignore.

* Added fallback to SSHA256 if environment is not proper prepared.

* No fallback within management frontend, as it must match to other components.

* Unified and corrected alignment; implemented support of SSHA512

* Currently, password_hash of PHP is using by default bcrypt (BLF). As this might change later, we must ensure, that BLF is still used after PHP changes its default.

* Switched to BLF-CRYPT by default (even on update)

* Switched to BLF-CRYPT by default (even on update)

* Adding information in config generation / update with link to supported hash algorithm

* Bump sogo version to 1.92

* Fallback to BLF-CRYPT in case password scheme is not proper defined for Mailcow administration.

data/web/inc/vars.inc.php

@@ -17,6 +17,7 @@ $database_name = getenv('DBNAME');
 
 // Other variables
 $mailcow_hostname = getenv('MAILCOW_HOSTNAME');
+$default_pass_scheme = getenv('MAILCOW_PASS_SCHEME');
 
 // Autodiscover settings
 // ===