Add a test verifying that lock-implication is honored
Add a test verifying that lock-implication is honored

Locks can be included in one another. This inclusion can be violated
in two ways, viz.,
- A holds a lock L and B holds an exclusive lock L belongs to, and
- A holds an exclusive lock and B holds a lock L belongs to.
Verify that this is not the case.

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

yiannist/ganeti,andir/ganeti,bitemyapp/ganeti,yiannist/ganeti,grnet/snf-ganeti,mbakke/ganeti,apyrgio/ganeti,leshchevds/ganeti,ganeti-github-testing/ganeti-test-1,ganeti/ganeti,mbakke/ganeti,dimara/ganeti,bitemyapp/ganeti,grnet/snf-ganeti,ganeti-github-testing/ganeti-test-1,dimara/ganeti,andir/ganeti,andir/ganeti,leshchevds/ganeti,leshchevds/ganeti,onponomarev/ganeti,onponomarev/ganeti,ganeti/ganeti,mbakke/ganeti,apyrgio/ganeti,ganeti/ganeti,yiannist/ganeti