Description of problem:
If there badly set permissions (700 - no kvm permissions) on directory from which administrator wants to create data domain, creation succeeds but fails when attempting to start VM that has image on mentioned domain. vdsm correctly prints messages about wrong permissions on image during start. I think it would be good to prevent such a situation by checking permissions during domain creation for groups as well.

Version-Release number of selected component (if applicable):
vdsm-4.9-84.el6.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Create local (or nfs) data-center
2. Make a directory (e.g. /mnt/local)
3. chown 36:36 /mnt/local; chmod 700 /mnt/local
4. Create data domain from this directory
  
Actual results:
Domain is created successfully

Expected results:
There is check that detects wrong permissions on the directory