BackupGuard 2.2.0, restore and Dolibarr update from the browser

This version adds three things.

• Restore from the browser. You upload the file, the module analyses it without changing anything, checks every SQL statement and makes a safety backup of the current state. You then follow the restore live, with "Retry" and "Go back to the previous state" if it stops halfway.
• Dolibarr update. The module offers the maintenance release and the next major version, checks the official package file by file against the checksums published by Dolibarr, and makes a full backup before writing anything.
• Restore to another database server, from MySQL to MariaDB for example.

On the security side, command line scripts now only answer on the command line, and every file of the update package is verified. The update is recommended.

After replacing the files, disable then re-enable the module.