gimp scripting support

[Federico Beffa <beffa@ieee.org>]

Hi,

I've updated the gimp in my profile and get the following errors:

Gtk-Message: Failed to load module "canberra-gtk-module"
Traceback (most recent call last):
  File "/gnu/store/9gnpd0vkwyvy6x7jiv1kjjdgf6gd1hjl-gimp-2.8.14/lib/gimp/2.0/plug-ins/gradients-save-as-css.py",
line 25, in <module>
    from gimpfu import *
  File "/gnu/store/9gnpd0vkwyvy6x7jiv1kjjdgf6gd1hjl-gimp-2.8.14/lib/gimp/2.0/python/gimpfu.py",
line 76, in <module>
    import gimp
ImportError: could not import pygtk


Given that 'pygtk' is now necessary, IMO it should be a propagated input.

Also, installing pygtk in my profile is not enough. This is because I
do use python-3, while gimp uses python-2. For this reason PYTHONPATH
doesn't work with gimp and I can't change it.

One solution is to define PYTHONPATH in a wrapper around gimp.

Regards,
Fede