…ter in the Breakpoint view
This reverts commit 95ae646.
Prior to this commit, users of IPython 1.0 and higher would be greeted with a deprecation warning like this: /home/pi/code/ipython/IPython/frontend.py:30: UserWarning: The top-level `frontend` package has been deprecated. All its subpackages have been moved to the top `IPython` level. This commit addresses that for newer version of IPython, preserving the old behavior if importing from the new location fails.