New level and Inputs settings for keyboard

- new level for physics tests
- inputs made for keyboard (up arrow to jump, w and x for kicks)
- change in player movements (deacceleration and punch kickback) for
more horizontal gameplay
Merging Upstream

Except Prototype.unity : error in merging
Fixing merge problem

Fixing merge issue with prototype.unity
Merge pull request #1 from aurelien974/master

New level and Inputs settings for keyboard