[arch-general] [PSA] change to locale handling

Hi guys, We recently (in [testing]) refactored our locale handling. This should hopefully resolve some long-standing issues, so I though I'd bring it to everyone's attention. For some details see: <https://plus.google.com/114015603831160344127/posts/2zKCcnTWDpa>. Please report any issues/bugs/regressions on the bug tracker. Cheers, Tom