[#31620] Some plugins cause blank pages in 3.1.4
Add test coverage to JPlugin constructor testing private vars
[#31607] REGRESSION: Changing the autoload order in a point release (Fix #1615)
Add test coverage to JLoader::registerPrefix()
[#31598] Fix for B/C break related to Tag saving using *old* way (Fix #1606)
Prepare 3.1.5 release
Correct duplicated update queries
Prepare master for development
 $ Updating installation lang files: ru-RU, sv-SE
Merge remote-tracking branch 'upstream/master' into defrules