gconf opaque data types

[Havoc Pennington <hp redhat com>]

Hi,

I want to hide some struct fields in gconf that people weren't
supposed to be using. I had to hack a few lines in the keybindings
capplet, but otherwise everything rebuilds fine after this
change. Michael is a big fan of doing this, though he isn't around.

If no one complains I'll commit soon.

Havoc