security fixes:
T128209: Reflected File Download from api.php. Reported by Abdullah Hussam.
T165846: BotPasswords doesn't throttle login attempts.
T134100: On private wikis, login form shouldn't distinguish between login failure due to bad username and bad password.
T178451: XSS when $wgShowExceptionDetails = false and browser sends non-standard url escaping.
T176247: It's possible to mangle HTML via raw message parameter expansion.
T125163: id attribute on headlines allow raw.
T124404: language converter can be tricked into replacing text inside tags by adding a lot of junk after the rule definition.
T119158: Language converter: unsafe attribute injection via glossary rules.
T180488: api.log contains passwords in plaintext wasn't correctly fixed.
T180231: composer.json has require-dev versions of PHPUnit with known security issues. Reported by Tom Hutchison.