Merge pull request #1 from anirban-c/master

xen: Add following scripts
Merge pull request #3 from anirban-c/master

Remove nicira-ids
Merge pull request #4 from anirban-c/master

Fix cloudstack-nic id parsing from config data
Fix scripts to safeguard agent from spurious add/deletes

Signed-off-by: Anirban Chakraborty <abchak@juniper.net>