Clippings for C19, C20, & C25

As mentioned in Zonals for the Current Cycle (C25), I located the TWIC clippings for C25, but didn't have time to add them to the clippings page for that cycle. Instead of that, I made some small, general corrections to the index of all World Chess Championship Zonals, and to the related pages for the individual cycles. Then I added a few odds and ends to the pages for Zonals 2000-2001 (C19) and Zonals 2001-2002 (C20).