Added unicodedata module import

This pull request fixes the following issue:

`2014-04-12 08:28:06,811 (-b500490) :  CRITICAL (agentkit:931) - Exception in the search function of agent named 'TVRage', called with keyword arguments {'show': 'American Dad!', 'id': '89', 'year': '2005'} (most recent call last):
  File "/volume1/Plex/Library/Application Support/Plex Media Server/Plug-ins/Framework.bundle/Contents/Resources/Versions/2/Python/Framework/api/agentkit.py", line 924, in _search
    agent.search(results, media, lang)
  File "/volume1/Plex/Library/Application Support/Plex Media Server/Plug-ins/TVRage.bundle/Contents/Code/__init__.py", line 25, in search
    media.show = unicodedata.normalize('NFC', unicode(media.show)).strip()
NameError: global name 'unicodedata' is not defined`