libct: set SOCK_CLOEXEC on sockets

We want to be sure, that children will not inherit these sockets.

Probably we need to think which file descriptors should be closed
in spawn_cb and enter_cb.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
go: reports errors from requests

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
go: handle interrupted connections

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>