socket: Move connect_to out of ph_socket class

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
socket: Move hash out of ph_socket class

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
socket: Poll accepting socket, do not block on accepting

This is required to make polling of not yet picked up side channels
to clean them up on demand.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
socket: Slightly more optimal socket picking-up

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>