compel: plugins,std -- Move in infect code

Providing infect functionality inside std plugin
doesn't look suite for me: the restorer has to define
dummy parasite_daemon_cmd/parasite_trap_cmd/parasite_cleanup
just to be able to compile with it.

So we have to define weak stubs right here in near future.

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>