Incompatibility with pygtkobject >= 2.90.1

[Julian Hall]

With pygtkobject >= 2.90.1, GnoMenu.py crashes on startup with the following exception:

jules@ubuntu-dev-vm:~/gnomenu$ /usr/lib/gnomenu/GnoMenu.py run-in-window
Traceback (most recent call last):
  File "/usr/lib/gnomenu/GnoMenu.py", line 26, in <module>
    from gi.repository import PanelApplet as gnomeapplet
  File "/usr/lib/python2.7/dist-packages/gi/__init__.py", line 23, in <module>
    from ._gi import _API, Repository
ImportError: could not import gobject (error was: ImportError('When using gi.repository you must not import static modules like "gobject". Please change all occurrences of "import gobject" to "from gi.repository import GObject".',))

For more info, see: https://bugs.launchpad.net/ubuntu/+source/pygobject/+bug/828751 and https://bugs.launchpad.net/ubuntu/+source/ubuntuone-control-panel/+bug/829186