Change map-hash from macro to fn
Rename clojure.lang.PersistentSortedMap to clojure.lang.PersistentTreeMap
Merge pull request #24 from patrickgombert/map-hash-fn

Map hash fn & PersistentTreeMap
Write left and right red-node assoc rebalance tests. Fixes add-left bug.
Remove duplicated namespace. Rename to validated and watched.
Merge pull request #25 from patrickgombert/tree-map-tests

Write left and right red-node assoc rebalance tests. Fixes add-left bug.
Merge pull request #26 from patrickgombert/cleanup-validated-and-watched

Remove duplicated namespace. Rename to validated and watched.