Argo user's manual version 2.4, Seoul update

This is the official version 2.4 of Argo user's manual, Seoul update, released on March 30th with its associated comments.

The version 2.4 of Argo user's manual is now officially released.

The new features, changes and updates of the manual were decided during the Argo data-management team meeting, held in Seoul in November 2011.
Many thanks to the 4 contributors who sent 4 feedbacks and comments on the user's manual Seoul update n°3.