track bugs reported upstream about cldr data

POSIX generation broken in recent version: http://unicode.org/cldr/trac/ticket/9445 (fixed upstream)

Bad AM/PM encoding for ru_RU: http://unicode.org/cldr/trac/ticket/9689 (fixed in r11798)

af_ZA abbreviated names: http://unicode.org/cldr/trac/ticket/9690 (was already fixed upstream)