Adds a 'sourcing guard' to backup.sh.
Its is responsible for preventing the 'main' execution when this
script is sourced by another script.
Also updates the 'copyright' in the header.
Merge branch 'master' of https://github.com/Adnn/MediaWiki_Backup
Adds a test for LocalSettings.php existence before reading it.
Also fixes several syntax errors.
Imports a 'restore.sh' scripts.
The script is able to restore the complete filesystem (not images only),
to create the database and the user in mysql, and to restore the sql dump.