Update build system to preserve obsolete translations

[jsbackus]

look at adding -no-obsolete to the call to lrelease. See @zzpxyx's comment in issue #3.

[jsbackus]

First attempt made in afb62e5

[jsbackus]

@zzpxyx's idea in #3 regarding different Make targets seems to be better. Need to look closer at share/antimicro/translations/CMakeLists.txt. I suspect we can add the three targets @zzpxyx suggested there and remove the two CMake targets. We'll need to keep the QT4 vs. QT5 ladder, but otherwise should be able to simplify the logic.

[jsbackus]

I looked at this some on Tuesday. Made a little progress, but it is complicated. I can see why @Ryochan7 did what he did...

[jsbackus]

Bailing on this for now. Will revisit at a later date.

[pktiuk]

AntiMicro is no longer maintained. There were no bigger fixes since 2017.
There is a new recommended version of this app called AntiMicroX.

As a part of cleanup, this issue will be closed and repository will be archived.
If you find this issue relevant also for that new version of application you can create a new issue (or discussion) there (but firstly check it, because many issues of the old app are fixed and there are some new functionalities implemented)
If you will decide to create a new issue for AntiMicroX remember to mention this issue for reference.