This follow up a manual merge of r101002 in REL1_18 made by r102535
Bug fix is:
(bug 29912) Unit tests break if parsertest tables are still present
* (bug 31822) Error during upgrade due to output buffer reset in stdout
* (bug 31913) Special:MostLinkedTemplates had an incorrect GROUP BY clause
under Microsoft SQL.
+* (bug 29912) Unit tests break if parsertest tables are still present
* (bug 31990) justify paragraphs pref adds extra space to category listing
=== API changes in 1.18 ===
suppressed
* (bug 31921) Magic words REVISIONDAY, REVISIONMONTH and REVISIONYEAR now give
current values on preview
-* (bug 29912) Unit tests break if parsertest tables are still present
* (bug 19186) Special:UserLogin's title on Special:SpecialPages now says
"create account" when the user cannot create an account
* (bug 31818) 'usercreated' message now supports GENDER