* conform/data/stdlib.h-data: Account for XPG6 changes.
* stdlib/stdlib.h (__random): Change return value type to long.
(posix_memalign): Cleanup parameter names.
(setenv, unsetenv): Make available for __USE_XOPEN2K.
Change return type of unsetenv to int.
(qecvt, qgcvt, qfcvt): Declare only if __USE_MISC.
* sysdeps/generic/setenv.c (unsetenv): Change return type to int.
Return -1 and set errno if parameter is invalid.
* stdlib/random.c (__random): Change return value type to long.