Implemented Exit menu item for the GameOvermenu.
Merge branch 'testing' into gameover_18

Conflicts:
	ISGPKBS/Game/Window.cpp
GameMenu now uses a shiny picture that says gameover.
Modified interfaces for IGameState.
Added gameOverGamestate.
GameOverGameState now takes exit/restart member fp's in the constructor.
Removed unused include.
Made some changes.
Level is now drawn with PlayingGameState.
GameStates switching now works.
Moved parralax scrolling to Level.cpp
Merge branch 'testing' into gameover_18

Conflicts:
	ISGPKBS/Game/Game.vcxproj
	ISGPKBS/Game/Game.vcxproj.filters
	ISGPKBS/Game/Level.cpp
	ISGPKBS/Game/Window.cpp
Parralax scrolling works again.
Merge branch 'testing' into gameover_18

Conflicts:
	ISGPKBS/Game/Game.vcxproj.filters
	ISGPKBS/Game/Level.h
	ISGPKBS/Game/Window.cpp