zdtm: shm test update

v2: cleanup issues fixed

What's new:
1) cloning to new IPC ns depends on built option.
2) Check for lookup shared segment by key added.
3) Check for creation new segnent after migration added.
4) Few check for syscalls results added.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Andrey Vagin <avagin@gmail.com>