Several fixes

- Fixed #619: Bug - HTTP Redirection - Null field - Update errors
- Refactoring + CS fixes + typo
- SETUP: Unable to backup - mysqldump is unavailable
- GUI: Added fix to re-encrypt md5 hash password using better algorithm available (users)
- GUI: Fixed: use crypt() to encrypt password instead of md5()
- GUI: Merged password_change.tpl templates into shared/partials/forms/password_update.tpl
- GUI: Removed useless files
- GUI: Rewritten the generateRandomSalt() function
- GUI: Use better available encryption algorithm as provided by crypt (only those available in the mainline glibc)
and a lot more...