Add new module 'Bienvenue'.

This module provides a simple  presentation of geophar.
Make new 'reload.png' icon.
New session management interface.

Also set 'param.ligne_commande' to 'False' by default, since this is used
only by advanced users.
Add pylint config file (needs to be tweaked).
[wx->Qt] Fix autosave.

This should end transition from wx to Qt !