Fix "'XenServer' object has no attribute 'device'".

Fixes ZEN-12978.
Merge pull request #7 from zenoss/feature/ZEN-12978

Please review branch feature/ZEN-12978
Release: Version 1.0.2dev -> 1.0.2.
Finished release 1.0.2.
Finished release 1.0.2.
Post Release: Version 1.0.2 -> 1.0.3dev.
VBDs impact their VM, not all VMs.

Fixes ZEN-13467.
Merge pull request #9 from zenoss/feature/ZEN-13467

Please review branch feature/ZEN-13467
Release: Version 1.0.3dev -> 1.0.3.
Finished release 1.0.3.
Finished release 1.0.3.
Post Release: Version 1.0.3 -> 1.0.4dev.
ZEN-13343: XenServer Analytics Enablement: Add Aliases to XenServer
add xenserver model graph
Merge branch 'feature/ZEN-13343' of https://github.com/zenoss/ZenPacks.zenoss.XenServer into feature/ZEN-13343
analytics for xenserver