message: Fix infinite pagination/glitches with pagination
  I think this was being caused by a bug introduced in 47f29b that meant that `backwards` was actually being used as `forwards`.
diff: @@ -345,7 +345,7 @@ module.exports = React.createClass({
  //
  // If backwards is true, we unpaginate (remove) tiles from the back (top).
  for (let i = 0; i < tiles.length; i++) {
  - const tile = tiles[backwards ? tiles.length - 1 - i : i];
  + const tile = tiles[backwards ? i : tiles.length - 1 - i];
  // Subtract height of tile as if it were unpaginated
  excessHeight -= tile.clientHeight;
  // The tile may not have a scroll token, so guard it
  