Switch to java.jdbc 0.2.0.


Hi Chris,

I updated org.clojure/java.jdbc to 0.2.0. The old
java.jdbc.internal was merged into the java.jdbc namespace.
Unfortunatly the do-prepared-return-keys fn is now marked as
private. I changed the call to @#'jdbc/do-prepared-return-keys
right now, but maybe we can ask @seancorfield to make this fn
public.

Roman.