Do cgroup parameters value check

cpu_shares >= 2
bklio_weight in [100, 1000]

Change-Id: Ic63d10960c8082873577460edd046c7d6ce35fb7
Bugfix: HostServersQos#__repr__ no "name" found

Change-Id: I537f9d14a849d83afabc653b74f17eabeafbbd43
Bugfix: HostServersQos#__repr__ no "name" found
Add instance name in list head

Change-Id: I80818c24f93ae316c5c4784227ebb56ddcf5a693