Generator should provide option for mobile version

[Clément Mathieu]

This option should rule the addition of the <meta name="viewport" ... />" to the index.html.

This raises several questions:

• should the application be user-scalable ? (knowing that some of our components do not scale very well, like sidepane)
• should all application have a minimal <meta name="viewport" content="width=device-width,initial-scale=1"/> ?
• how to clearly present those choices to the user using generator questions ?