emacs conflicts with gnome-settings-daemon

[Zhang Wei]

There's a lot of report from chinese Emacs community that Emacs conflicts
with gnome-settings-daemon.

`C-<SPC>' is widely accepted as the hot-key to activate XIM input method
such as SCIM or fcitx in chinese linux community. But when
gnome-settings-daemon is running, `C-<SPC>' is swallowed by emacs and
not passed to the system, it's really a big trouble because that mean's
you can't input chinese with XIM in Emacs.

I'm not sure it's a bug of GNOME or Emacs, but only Emacs users observed
this phenomenon, so I report it here.