make the keepAlive optional
make the keepAlive optional

Instead of using undefined or dummyIORef for the keepAlive of those
Sample values which don't need a finalizer, let's use Nothing.

jam40jeff/sodium,jam40jeff/sodium,kevintvh/sodium,jam40jeff/sodium,jam40jeff/sodium,jam40jeff/sodium,kevintvh/sodium,kevintvh/sodium,kevintvh/sodium,jam40jeff/sodium,kevintvh/sodium,kevintvh/sodium,kevintvh/sodium,jam40jeff/sodium,kevintvh/sodium,jam40jeff/sodium