Ajout de timer

Ajout de la classe clTimer qui permettra plus tard de mieux gérer les
FPS.
Merge branch 'master' into Unstable

Conflicts:

SDL_2.0.3_Template.xcodeproj/project.xcworkspace/xcshareddata/SDL_2.0.3_
Template.xccheckout

SDL_2.0.3_Template.xcodeproj/project.xcworkspace/xcuserdata/rlariviere94
.xcuserdatad/UserInterfaceState.xcuserstate