Removed "How to Design Faceted Search"

Link to a "buy now" page with no signs of free stuff

free-programming-books.md

@@ -227,7 +227,6 @@
 
 ### Graphical User Interfaces
 * [Best of Smashing Magazine](http://anniversary.smashingmagazine.com/best-of-smashing-magazine.zip)
-* [How to Design Faceted Search: The Complete Guide to Designing Faceted Search User Interface](http://leanpub.com/howtodesignfacetedsearch) - Abhijit Rawool
 * [Programming with gtkmm 3](https://developer.gnome.org/gtkmm-tutorial/stable/)
 * [Search User Interfaces](http://searchuserinterfaces.com/book/) - Marti A. Hearst
 * [Working through Screens](http://www.flashbulbinteraction.com/WTS.html) - Jacob Burghardt