Use the AppleLanguages preference instead of AppleLocale on OS X and iOS

AppleLocale is for things like date formats, it seems, while the first
entry in AppleLanguages contains the user's preferred UI language. I
think that is closer to what we want here.

Note that in AppleLanguages, the country (where present) is separated
from the language with a hyphen, while in AppleLocale an underscore is
used.

Change-Id: I6d8a728d53ca6b46e8fcf0e333a6d0aa34abff1d

sal/osl/unx/osxlocale.cxx

@@ -48,7 +48,7 @@ namespace
     */
     CFStringRef getProcessLocale()
     {
-        CFPropertyListRef pref = CFPreferencesCopyAppValue(CFSTR("AppleLocale"), kCFPreferencesCurrentApplication);
+        CFPropertyListRef pref = CFPreferencesCopyAppValue(CFSTR("AppleLanguages"), kCFPreferencesCurrentApplication);
         CFPropertyListGuard proplGuard(pref);
 
         if (pref == NULL) // return fallback value 'en_US'
@@ -72,7 +72,7 @@ int macosx_getLocale(char *locale, sal_uInt32 bufferLen)
 
     // split the string into substrings; the first two (if there are two) substrings
     // are language and country
-    CFArrayRef subs = CFStringCreateArrayBySeparatingStrings(NULL, sref, CFSTR("_"));
+    CFArrayRef subs = CFStringCreateArrayBySeparatingStrings(NULL, sref, CFSTR("-"));
     CFArrayGuard arrGuard(subs);
 
     CFStringRef lang = (CFStringRef)CFArrayGetValueAtIndex(subs, 0);