Implement #7495 as per Matt and Ingo's suggestions.

The various LC_ environment variables (as well as LANG) are set in
/etc/profile, based on the output of this new simple bin command locale.
LANG and LC_CTYPE are set based on the first preferred language, whereas the
formatting variables are all set based on the formatting conventions language.

The list of LC_ variables are from the locale command on Linux.

Based on my testing, at least the date command obeys these variables.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42394 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/bin/locale/Jamfile

@@ -11,3 +11,5 @@ BinCommand collectcatkeys : collectcatkeys.cpp RegExp.cpp
 BinCommand linkcatkeys : linkcatkeys.cpp : be liblocale.so $(TARGET_LIBSTDC++) ;
 
 BinCommand dumpcatalog : dumpcatalog.cpp : be liblocale.so $(TARGET_LIBSUPC++) ;
+
+BinCommand locale : locale.cpp : be liblocale.so $(TARGET_LIBSUPC++) ;