Make hspace correctly handle --independent-groups
Make hspace correctly handle --independent-groups

In the presence of capacity checks, first verify all groups for
present violations of global N+1 redundancy. Then mark the non-redundant
groups as unallocatable and ignore then in future checks.

Signed-off-by: Klaus Aehlig <4ce51de36d9068cd7db2eec1151e0f3f95419008@google.com>
Reviewed-by: Petr Pudlak <9d19625f8ee825a2c398462ed335cbcf98f79c32@google.com>

andir/ganeti,andir/ganeti,mbakke/ganeti,mbakke/ganeti,onponomarev/ganeti,leshchevds/ganeti,yiannist/ganeti,leshchevds/ganeti,yiannist/ganeti,ganeti/ganeti,onponomarev/ganeti,mbakke/ganeti,yiannist/ganeti,leshchevds/ganeti,ganeti/ganeti,ganeti/ganeti,andir/ganeti