add get-compatibility-mode

Author: edma2

src/msgpack/core.clj

@@ -13,6 +13,8 @@
 (defn set-compatibility-mode
  ([] (set-compatibility-mode true))
  ([value] (swap! compatibility-mode (fn [_] value))))
+ 
+(defn get-compatibility-mode [] @compatibility-mode)
 
 (def ^:private ^Charset
  msgpack-charset