$context: RequestContext object
'PageHistoryLineEnding': Right before the end <li> is added to a history line.
-$row: the revision row for this line
-$s: the string representing this parsed line
-$classes: array containing the <li> element classes
+$historyAction: the action object
+&$row: the revision row for this line
+&$s: the string representing this parsed line
+&$classes: array containing the <li> element classes
'PageHistoryPager::doBatchLookups': Called after the pager query was run, before
any output is generated, to allow batch lookups for prefetching information