+'SpecialSearchResultsPrepend': Called immediately before returning HTML
+on the search results page. Useful for including an external search
+provider. To disable the output of MediaWiki search output, return
+false.
+$specialSearch: SpecialSearch object ($this)
+$output: $wgOut
+$term: Search term specified by the user
+
+'SpecialSearchResultsAppend': Called after all search results HTML has
+been output. Note that in some cases, this hook will not be called (no
+results, too many results, SpecialSearchResultsPrepend returned false,
+etc).
+$specialSearch: SpecialSearch object ($this)
+$output: $wgOut
+$term: Search term specified by the user
+