Early Access v 0.6 - tutorial & language

As the release is a lot closer now, updates are happening more often. Let's hope the game (and its dev :-) won't break.

This version includes :

• Single: renewed tutorial to reflect the last improvements to the control scheme. Also, the tutorial is shorter and less messy towards the end.
• Single: correction of sound levels.
• Single: new music for Ulysse, Curbas (dance) and Hephaestos levels. If you don't want to play the game again to see curbas, here is what it looks like (spoiler!!) https://www.youtube.com/watch?v=Rfz60ZHj870
• Single: small corrections on the "How to play" page.
• Single: replugged French version.

Next job will be to work on trading cards. I have an idea that could be nice for that one...