mw regression jobs now use shell script

This migrate the MediaWiki core regression jobs to use the shell script
file mw-run-phpunit.sh. Since it logs the junit output to a different
filename, use the phpunit-junit-2 macro which match it.

Also apply the archive-log-dir to keep a copy of LocalSettings.php,
junit XML files and the debug logs.

Jobs updated:

mediawiki-core-code-coverage
mediawiki-core-regression-REL1_19
mediawiki-core-regression-REL1_20
mediawiki-core-regression-REL1_21
mediawiki-core-regression-master

Change-Id: I72eac56623add6db5dd07304694dd93124a21779