New cask wallpaper-clocks: fancy dynamic desktop clocks

This creates a new cask for Vlad Studios' [Wallpaper Clocks](http://www.vladstudio.com/wallpaperclocks/)--an oldie but a goodie.

The download link appears to be a redirect for hit-counting purposes, but since it too is on Vlad Studios' website, I elected to leave it the way it is. Let me know if it should be edited, though.