improve deprecation, start changelog

--HG--
branch : trunk

py/impl/log/warning.py

@@ -13,14 +13,18 @@ class Warning(DeprecationWarning):
 def _apiwarn(startversion, msg, stacklevel=2, function=None):
     # below is mostly COPIED from python2.4/warnings.py's def warn()
     # Get context information
-    if stacklevel == "initpkg":
-        frame = sys._getframe(stacklevel == "initpkg" and 1 or stacklevel)
-        level = 2
+    if isinstance(stacklevel, str):
+        frame = sys._getframe(1)
+        level = 1
+        found = frame.f_code.co_filename.find(stacklevel) != -1
         while frame:
             co = frame.f_code
-            if co.co_name == "__getattr__" and co.co_filename.find("initpkg") !=-1:
-                stacklevel = level 
-                break
+            if co.co_filename.find(stacklevel) == -1:
+                if found:
+                    stacklevel = level 
+                    break
+            else:
+                found = True
             level += 1
             frame = frame.f_back
         else: