Merge branch 'hotfix/1.7.4'
Preserve language for default revision flags #1484
Fix external keys with onlytopic.in.map #1489
Improve topic merge unit test with non-ASCII characters in IDs #1491
Add URI cleaner with non-ASCII output #1491
Fix non-ASCII IDs in topic merge #1491
Merge branch 'hotfix/1.7.5' into develop

Nothing to merge, hotfix features were backported from develop.