Fixing many issues :
* solved issues with Image update
* solved issues with Slider update
* now able to add components to a Layout without resizing them into a grid
ManageGameMenu presents players following data:
* introduced 3 aspects ratio for resizing and updating Image class
* correction of bugs in Slider class
* dynamic add of a player and connection to event clic
NewGameMenu imrpoved and almost ready :
* dynamic management of the levels button in the ChooseYourLevelMenu
* NewGameMenu displays avatars