- winlock.c does not exist anymore, so do not try to compile it. This

  only affects zpkg.

Note: I feel terrible modifying a tag, but I feel not qualified to do a 
      ZODB release. Also, the change only affect zpkg which uses a 
      checkout only and not the egg. No other system looks at SETUP.cfg 
      anyways.

src/ZODB/SETUP.cfg

 # Extension information for zpkg.
-
-<extension winlock>
-  source winlock.c
-</extension>