Added binding for SDL_SetTextureColorMod and SDL_GetTextureColorMod and updated the Freetype sample to use it for setting the color of text

#{
fib <- :n {
  if: n < 2 {
    1
  } else: {
    (fib: n-1) + (fib: n-2)
  }
}

main <- {
  print: (string: (fib: 30)) . "\n"
}

}