Convert all input routines, and most internal strings, to use
wide-character functions. All extended characters are supported,
including those having column widths of zero (eg, combining characters),
one (eg, normal Western characters) and two (eg, many East Asian
characters). This was quite a major undertaking!
Some versions of getopt_long() show ALL options if an ambiguous
abbreviation was supplied (such as "--no"), and we don't really want
players to discover this option by accident, do we? :-)
Changing just the LC_NUMERIC part of the locale DOES work, if you read
the manual page carefully! In particular, TWO calls need to be made, the
first with parameter NULL to get the current locale. In addition, the
result MUST be copied to a new string, as it may be (and is!) overwritten
by the next call to setlocale().
For some reason, changing the locale to "C" for LC_NUMERIC, then
restoring just that part of the locale to the old user-supplied
one does not work. Simply reinstating the whole locale using
setlocale(LC_ALL, ""), however, DOES work, so do that.
