core, use locale-aware sorting of letters on on-screen keyboard
This changes the ordering of the letters on the on-screen keyboard to be locale aware. For example, before this change, the letter ordering for Norwegian Nynorsk (nn_NO.utf8 locale) was:
abc...xyzåæø
After this change, it is
abc...xyzæøå
^^^
which is the official order of the letters in this alphabet.