[pygtk] pygtk parallel install

[James Henstridge]

I have just checked in changes to pygtk and gnome-python (both 1.2 and 
2.0 branches) to make parallel install easier.

Here is a small summary of how it works:

1. each major version of pygtk (1.2, 2.0, etc) installs under:
      $(prefix)/lib/python?.?/site-packages/gtk-x.y

2. each version of pygtk installs a file called pygtk.pth into:
      $(prefix)/lib/python?.?/site-packages
   containing a single line: gtk-x.y

3. each version of pygtk installs the file pygtk.py into
      $(prefix)/lib/python?.?/site-packages
   This file is identical for all pygtk versions.

Addon packages install into the appropriate gtk-x.y directory.

Results are:
a. Files for individual pygtk "platforms" are kept separate, and
   prevented from being imported together.

b. sysadmins and/or distributors can decide which version of pygtk
   is the default by adjusting pygtk.pth

c. Programs can request a particular major version of pygtk with:
      import pygtk ; pygtk.require('x.y')
   If they want a particular version, this can be followed with an
   assert:
      import pygtk ; pygtk.require('2.0')
      import gtk
      assert gtk.pygtk_version >= (1,99,12), 'pygtk version too old'


James.

-- 
Email: james@daa.com.au              | Linux.conf.au   http://linux.conf.au/
WWW:   http://www.daa.com.au/~james/ | Jan 22-25   Perth, Western Australia.