vc-revert broken for Subversion files

[Bob Rogers]

   To reproduce:

   1.  Make a small change to a file registered under Subversion,
"foo.el" for example.

   2.  "emacs -Q foo.el"

   3.  "C-x v u".  The operation will fail with the following message:

        vc-stay-local-p: Symbol's function definition is void: remove-if-not

I am using an emacs built from the trunk about 36 hours ago.  FWIW, this
worked in my previous trunk build two week ago.  vc-revert also still
works with CVS files.

   TIA,

                                        -- Bob Rogers
                                           http://rgrjr.dyndns.org/