Removed the French translation of the Play2 tutorial

I've removed the French translation of the Play2 tutorial because I don't
really feel like maintaining it. That being said, it's easy to bring it back to
life.

(@skyluc, please, don't take offense for this, and feel free to update the
French tutorial.)
Updated Play tutorial for Play 2.1 and Scala IDE 3.0.0

I have only updated the text, not the images, as this is cumbersome and
I think having un up-to-date text is sufficient to understand the tutorial.

Fixes #53