Deprecated C-x bindings

[Romain Francoise <romain@orebokech.com>]

The following bindings were marked as deprecated in Emacs 20:

 C-x /  (point-to-register-compatibility-binding)
 C-x j  (jump-to-register-compatibility-binding)
 C-x x  (copy-to-register-compatibility-binding)
 C-x g  (insert-register-compatibility-binding)

There are equivalent bindings in the C-x r map, which is the logical
place for register commands.

We might want to use these keys for more interesting things in the
future, so now (before the release) would be a good time to reclaim
them.

-- 
Romain Francoise <romain@orebokech.com> | The sea! the sea! the open
it's a miracle -- http://orebokech.com/ | sea! The blue, the fresh, the
                                        | ever free! --Bryan W. Procter