lupdate can be removed, sure. Anyway, this is just full of hacks.

Well, I guess the first version was the best after all. Can be made like this:

1. qm files stay in repo, preventing any kind of RCC errors
1. add extra `CONFIG` option(s)
1. extra targets are wrapped in `CONFIG` check

This way a developer build will not trigger any ts/qm updates; and release build configured with extra options like `CONFIG += ts_release` will have latest translations if they want to.
<hr>
P.S. I wanted to ask if removing obsolete entries from translations should be done by translators. I don't see any backporting going on, so this should be ok.