Update version requirement to 2.5, since that's what we're using anyway.

Fixes https://bugs.launchpad.net/ipython/+bug/505090

IPython/__init__.py

@@ -1,64 +1,63 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
 IPython.
 
 IPython is a set of tools for interactive and exploratory computing in Python.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2009  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 import sys
 from IPython.core import release
 
 #-----------------------------------------------------------------------------
 # Setup everything
 #-----------------------------------------------------------------------------
 
-
-if sys.version[0:3] < '2.4':
-    raise ImportError('Python Version 2.4 or above is required for IPython.')
+if sys.version[0:3] < '2.5':
+    raise ImportError('Python Version 2.5 or above is required for IPython.')
 
 
 # Make it easy to import extensions - they are always directly on pythonpath.
 # Therefore, non-IPython modules can be added to extensions directory
 sys.path.append(os.path.join(os.path.dirname(__file__), "extensions"))
 
 #-----------------------------------------------------------------------------
 # Setup the top level names
 #-----------------------------------------------------------------------------
 
 # In some cases, these are causing circular imports.
 from IPython.core.iplib import InteractiveShell
 from IPython.core.embed import embed
 from IPython.core.error import TryNext
 from IPython.testing import test
 
 from IPython.lib import (
     enable_wx, disable_wx,
     enable_gtk, disable_gtk,
     enable_qt4, disable_qt4,
     enable_tk, disable_tk,
     set_inputhook, clear_inputhook,
     current_gui, spin,
     appstart_qt4, appstart_wx,
     appstart_gtk, appstart_tk
 )
 
 # Release data
 __author__ = ''
 for author, email in release.authors.values():
     __author__ += author + ' <' + email + '>\n'
 __license__  = release.license
 __version__  = release.version
 __revision__ = release.revision