Changes for clojure.contrib.combinatorics/permutations

tltjr on Sun, 09 Jan 2011
Clojure=> (permutations [1 2 3])
((1 2 3) (1 3 2) (2 1 3) (2 3 1) (3 1 2) (3 2 1))
Clojure=> (permutations [1 1 2])
((1 1 2) (1 2 1) (1 1 2) (1 2 1) (2 1 1) (2 1 1))