- We used to round long double arguments to double. Now we print
them properly.
- Bugs involving '%F', corner cases of '#' and 'g' format
specifiers, and the '.*' precision specifier have been
fixed.
- Added support for the "'" specifier to print thousands' grouping
characters in a locale-dependent manner.
- Implement the __vfprintf() side of hexadecimal floating point
support. All that is still needed is a routine to convert the
mantissa to hex digits one nibble at a time in the style of ultoa().
Reviewed by: silence on standards@