[JustAMan]

No, what I'm saying is, currently we have, say, locale-ru_RU.jar in update-blala-ru_RU-install.bin
I propose having locale-5.0.0-ru_RU.jar, locale-5.0.3-ru_RU.jar, etc. That would bloat a bit the size of updates but it would let us stop worrying about incompatible (i.e. those we'd be unable to backport) changes in the properties.

If you object having different, but compatible, .jars, then we can still use different .jars for incompatible changes, like having locale-5.0.0-5.0.3-ru_RU.jar and locale-5.0.4-5.x.x-ru_RU.jar (this is named pretending 5.0.4 breaks backward compatibility).

I still think we should put different .properties to different Git branches, however that probably implies we'd have to have full copies of source properties there, not only differences (I dunno if it's possible in git to "checkout" in the same folder two branches at the same time).