change threading.getIdent to a property

This is new in 2.6 so now need to worry about backwards compatibility :)
diff --git a/Lib/threading.py b/Lib/threading.py
index d88f1be..e1a0b2a 100644
--- a/Lib/threading.py
+++ b/Lib/threading.py
@@ -663,7 +663,8 @@
 
     setName = _old_api(set_name, "setName")
 
-    def get_ident(self):
+    @property
+    def ident(self):
         assert self.__initialized, "Thread.__init__() not called"
         return self.__ident