Removed dependency on "frontend" module(depreceated) for ipython ver>1.0

From ipython 1.0 changelog (http://ipython.org/ipython-doc/rel-1.0.0/whatsnew/version1.0.html):  
<quote>We have removed the frontend subpackage, as it caused unnecessary depth. So what was IPython.frontend.qt is now IPython.qt, and so on.</quote>