#22 SSortTable sort arrows

[Jason Yip]

- Click once, sorts ascending
- Click twice, sorts descending
- Click thrice, arrow disappears but sorting doesn't
change
- Click again to start over

So there's some wierdness happening with the third
click.

According to the version tag, this is the latest version of
SSortTable though I'm using Scope 1.0.1 release.