New Features and improvements

[OlivierFL]

Features

• Add an ending date to tasks #30
• Add a public/private property to tasks #31
• Add email notifications (user account validation, tasks updates, etc.) #32
• Add pagination for tasks and users lists #33
• Add filters in tasks list (by author, creation date, etc.) #34
• Update the login form to use the Symfony's FormType #35
• Enable file uploading as task attachment #37
• Fix the user update logic (don't ask for password) #38
• Add user profile #39
• Fix the broken "afficher les tâches terminées" link on homepage, add the related template and page #40
• Update Bootstrap #36
• Update the design, better responsive on mobile #41