add refer-clojure exclude on abs

Author: puredanger

src/main/clojure/clojure/algo/generic/math_functions.clj

@@ -21,6 +21,7 @@
            functions such as sqrt or sin as multimethods that can be
            defined for any type."}
   clojure.algo.generic.math-functions
+  (:refer-clojure :exclude [abs])
   (:require [clojure.algo.generic.arithmetic :as ga]
             [clojure.algo.generic.comparison :as gc]))