implemented a View class to render views from the view folder
added Backup controller class + its views

and some helper classes
added header and footer views that can be embedded in other views
affichage du temps écoulé depuis la dernière sauvegarde
fixed closing tag
display no birthdays instead of empty list
added vertical-align property for icone class
added some space in the todo list
added menu.inc.php view required by header

+ added User class to check user logged and privileges
+ added Tools class that defines the redirect method
+ added MiniMail class to get count of minimails
+ added Db->scalar method
don't show list if no backups
change some titles
added a button to create new backup

Also, manage display of result of new backup on the list view.

The result of the backup creation is stored in a FlashBag before
redirecting to the list.
implemented backup file writing
fixed some style and display saved backup filename
display only backups matching regex
implemented backup delete
added a block system for views
changed some visuals
Adapted check-copyright script to allow exceptions
put the notices in a closable div