Introcuce os-posix.c and move posix specific signal handling
there.
Signed-off-by: NJes Sorensen <Jes.Sorensen@redhat.com>
Acked-by: NJuan Quintela <quintela@redhat.com>
Acked-by: NRichard Henderson <rth@redhat.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>