clib2 Code

- Getting ready for the 1.192 release.

- Floating point output in hexadecimal notation can now show a sign
in front of the hex prefix string.

- fflush() no longer calls flockfile()/funlockfile() with a NULL parameter.

- Removed the old isinf() and isnan() functions.

- Added isunordered(), isgreater(), isgreaterequal(), isless(),
islessequal() and islessgreater() to <math.h> for C99.

- The wchar_t type is now an 'unsigned short' integer (16 bits wide).

- Added PTRDIFF_MIN/PTRDIFF_MAX, WCHAR_MIN/WCHAR_MAX and
WINT_MIN/WINT_MAX to <stdint.h> for C99.

- Added imaxdiv() and imaxabs() for C99.

- Added strtoimax() and strtoumax() for C99.

- Added nextafter() and nextafterf() for C99.

- Added copysign() and copysignf() for C99.

- Unless I missed something, clib2 should now be functionally complete
with regard to C99, except for the floating point operations covered.
These are a major challenge all by themselves, and I wonder both
whether they are worth the effort and how one could implement them
correctly.

- fflush() now consistently supports a NULL parameter, causing all
streams to be flushed for which this behaviour is defined.

- Added isblank().

- The strftime() %z conversion now prints the time zone difference as a
"decimal" number. That is, if the difference is 5 hours and 30 minutes,
then %z will now print "530" rather than "330".

- mktime() now handles one leap second gracefully.

- Corrected the thread-safe clearerr() macro.

- Fixed math_headers.h so that fabsf.c compiles correctly with SAS/C.

- Added "fstat_stdout_test".

- Small fixes to the scanf() family.

- Hid two more program files.

- Added test cases for C99 format conversions.