tested by creating domr and user vm and migrating them
1. if you add host for kvm , you need specify kvm://ip_address, otherwiset there is no to differ kvm and xenserver hosts, edison cloud you please test this, may need some minor fixes.
2. if you want to session inside your plugin call, you can not use the one which is passed in, due to it is a slavesession, you need to call get_xapi_session() to get a new local session and use it. I have modified some of these, I may ignore some. Please let me know if you see XENAPI_PLUGIN_EXCEPTION.
The sequence:
1. add host in UI
2. scp setup_agent.sh to agent host, and execute it. This script receives hostip,zoneid, podid and guid, then runs "cloud-setup-agent" and "cloud-setup-console-proxy". Here, we assume that network/hostname and cloud-agent are already configed and installed.
3. Write a dummy kvm resource into the database, then wait for agent connects to server, by polling the database for every 1 minutes. If it finds the agent is in UP state in database, then return, or wait for at least 10 minutes.
