This patch is the first in a series that aims at cleaning up the
public C library headers (which end up being distributed with the NDK).
<resolv.h> and <time.h> contain declarations that should not be public.
They are used by other parts of the platform, but NDK applications should
not use or rely on them.
So copy them to private <bionic_time.h> and <resolv_iface.h> headers
and use a guard macro to avoid conflicts when both headers are included
at the same time.
The idea is that we're going to fix the other platform modules to
include these private headers. After this is done, we will remove the
duplicate definitions from <resolv.h> and <time.h>
Change-Id: I121c11936951c98ca7165e811126ed8a4a3a394d
