criu: pie,log -- Prepate to move into compel std plugin

 - Add uapi header and start using it
 - Add std_ prefix into functions and constants
 - Drop unneeded headers

travis-ci: success for compel: The final infect move and install target
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>