Add an unique index
Add to drop table
Add lease_policy_container and ip_lease_container_ip_lease
Fix sql debugging
Add a deletion test for many to many relation
Add a deletion test for one to many relation
Add relation between laase policy and ip lease container
Merge pull request #218 from axsh/feature-ip-lease-container

Feature ip lease container
Merge remote branch 'origin/master' into optimize-match-item