Returns the active game object. (The one shown in the inspector).

It will also return game objects that might be prefabs or non-modifyable objects.

	// Rotates the selected Game Object +45 degrees if the user presses 'g'
	// or -45 degrees if the user presses 'Shift + g'
	// If no object is selected, the Menus are grayed out.
	@MenuItem ("Example/Rotate Green +45 _g")
	static function RotateGreenPlus45() {
		var obj = Selection.activeGameObject;
		obj.transform.Rotate(Vector3.up*45);
	}
	@MenuItem ("Example/Rotate Green +45 _g", true)
	static function ValidatePlus45() {
		return Selection.activeGameObject != null;
	}

	@MenuItem ("Example/Rotate green -45 #g")
	static function RotateGreenMinus45() {
		var obj = Selection.activeGameObject;
		obj.transform.Rotate(Vector3.down*45);
	}
	@MenuItem ("Example/Rotate green -45 #g", true)
	static function ValidateMinus45() {
		return Selection.activeGameObject != null;
	}