Fix for plurals handling in russian an other languages on Android 2.x

Android 2.x handles only "one" and "other" values for plurals in most languages, and ignores others - that's wrong.
Problem is well known and described here: https://code.google.com/p/android-i18n-plurals/
Solution is also borrowed from that project.

This is fixed in Android 3+, and this patch fallbacks to default behaviour for those versions.