New WISEnut Review & Other Showdown Updates

Added a WISEnut review and have added the new WISEnut to the Search Engine Feature Chart, Search Engines by Feature Page, and the Review Page. Those pages were also updated by removing NBCi (now just serving GoTo results) and iWon (primarily serving GoTo results). Excite review updated to note site clustering. Updated case sensitive searching section on AltaVista Review and the Search Engines by Feature Page. Fast Review updated with information about using parentheses for OR: (term1 term2).