2015-04-16 Migration to IPython 3.1

It took me some time to do the migration to IPython 3.1. The code which automatically generates the documentation had to be updated to follow the new format of the notebooks. I had to redo the configuration of ipython to have the graph inline… I hope ipython does not rename itself into jupyter. The design is better but the notebooks crash from time to time. I guess the code becomes better each time a migration happens. But it takes quite some time. However, the changes are not reversible. Ipython needs to be updated otherwise the automated generation of the documentation will not work. For Jenkins, just remind that the server needs your credentials othewise it does not easily find pandoc.