[misc.c misc.h configure.ac openbsd-compat/openbsd-compat.h]
[openbsd-compat/timingsafe_bcmp.c]
Add timingsafe_bcmp(3) to libc, mention that it's already in the
kernel in kern(9), and remove it from OpenSSH.
ok deraadt@, djm@
NB. re-added under openbsd-compat/ for portable OpenSSH
