Partially revert r979476.
Partially revert r979476.

* subversion/libsvn_wc/wc.h
  (SVN_WC__SINGLE_DB,
   SINGLE_DB): Keep this a comment.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion