test: bers -- Initial commit

bers stads for berserker which should eat computer
resources emulating "load" for CRIU performance testing.

It's still far from being complete but can do trivial things:

 - generate mmap's with memory dirtified
 - open files

Nothing serious.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>