introduce a utility function in path :

getDahuFileFromDirectory : Get the name of the presentation file to
create when we create a new project, it is calculated from the name of the Directory.
introduce a Directory chooser window in the kernel
add the new project button in the menu
Handle the creation of a new project
Fortify conditions on screen view :

This is important for when we want to create a new project
with no screens on screencastn or when we initialize the workspace with
no screen.