Patch: CVS "missing files" (try 2)

Folks,

Tested in practice, my last patch to Tailor CVS code that was locally
creating files which didn't get created by update action (since
repository no longer knew antyhing about them) was not too great.

Instead of creating missing files, here's now a patch that removes 
missing paths from changeset.entries, so that they are simply discarded
(which is the right thing to do).

I don't yet know how will this work if all files from a specific
changeset are "missing" and the changeset ends up with an empty
'entries' list, but that's another story.

As usual, Lele if you improve the patch and commit it, let me know,
I'd rather be testing official stuff from darcs repository 
than my local patches ;)

Rgds,
-doc