Add a passive class for representing inherited live-locks
Add a passive class for representing inherited live-locks

Since job processes inherit their live-lock files from the master
process, they don't directly work with the file, they just need to use
the name.

This class exposes the same interface as LiveLock for such pre-created
livelocks.

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

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