Added recipe for manipulating SQL database via clojure.java.jdbc.

Hi Ryan,

I added the final recipe in the "mini-series": Manipulating an SQL database (via clojure.java.jdbc).
I also cross-linked this and the other two recipes in the series. Numerous small cleanups and corrections throughout.

Please note the authorship and attribution comment at the top of the Manipulating recipe: this is the wording approved by Sean Corfield for that recipe (the other two recipes were done independently). Sean will sign contributor agreement, if required, even though the terms of the docs I re-mixed are CC BY 3.0 (http://creativecommons.org/licenses/by/3.0/), which says:
"You are free: to Share — to copy, distribute and transmit the work, to Remix — to adapt the work, to make commercial use of the work"
     cheers, -t