Fix frontend tests so they obtain the right global test IPython object.

IPython/frontend/tests/test_prefilterfrontend.py

@@ -20,7 +20,7 b' import sys'
 from nose.tools import assert_equal
 
 from IPython.frontend.prefilterfrontend import PrefilterFrontEnd
-from IPython.core.ipapi import get as get_ipython0
+from IPython.testing.globalipapp import get_ipython
 from IPython.testing.tools import default_argv
 
 #-----------------------------------------------------------------------------
@@ -60,7 +60,7 b' def isolate_ipython0(func):'
         with arguments.
     """
     def my_func():
-        ip0 = get_ipython0()
+        ip0 = get_ipython()
         if ip0 is None:
             return func()
         # We have a real ipython running...