copy `__spec__` in shim module

for Python 3.4

IPython/utils/shimmodule.py

@@ -1,39 +1,42 b''
 """A shim module for deprecated imports
 """
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
+import sys
 import types
 
 class ShimModule(types.ModuleType):
 
     def __init__(self, *args, **kwargs):
         self._mirror = kwargs.pop("mirror")
         super(ShimModule, self).__init__(*args, **kwargs)
+        if sys.version_info >= (3,4):
+            self.__spec__ = __import__(self._mirror).__spec__
 
     def __getattr__(self, key):
         # Use the equivalent of import_item(name), see below
         name = "%s.%s" % (self._mirror, key)
 
         # NOTE: the code below was copied *verbatim* from
         # importstring.import_item. For some very strange reason that makes no
         # sense to me, if we call it *as a function*, it doesn't work.  This
         # has something to do with the deep bowels of the import machinery and
         # I couldn't find a way to make the code work as a standard function
         # call.  But at least since it's an unmodified copy of import_item,
         # which is used extensively and has a test suite, we can be reasonably
         # confident this is OK.  If anyone finds how to call the function, all
         # the below could be replaced simply with:
         #
         # from IPython.utils.importstring import import_item
         # return import_item('MIRROR.' + key)
 
         parts = name.rsplit('.', 1)
         if len(parts) == 2:
             # called with 'foo.bar....'
             package, obj = parts
             module = __import__(package, fromlist=[obj])
             return getattr(module, obj)
         else:
             # called with un-dotted string
             return __import__(parts[0])