<sys/bitops.h> needs <sys/types.h>

[Martin Husemann <martin%duskware.de@localhost>]

Trying to compile a sample from the bitops man page fails,
#include <sys/bitops.h> is not enough, as the __BITMAP_* macros use NBBY
to convert from bit indices to bytes.

I would just add #include <sys/types.h> to the synopsis in the man page,
but given how stupid that constant 8 is - should we instead make the
sys/bitops.h header default to 8 bits per byte if NBBY is not defined?

Martin