Updates #2767
This change adds these Kage functions: * imageDstOrigin * imageDstSrc * imageSrcNOrigin * imageSrcNSrc and deprecates these functions: * imageDstRegionOnTexture * imageSrcRegionOnTexture Closes #1870
// +build
Closes #2325
FinalScreenDrawer is an interface for a custom screen rendering. If a game implements FinalScreenDrawer and is passed to RunGame, its DrawFinalScreen is called after Draw. Also this adds `-crt` option to examples/flappy. Closes #2046