CLOUDSTACK-7754: Templates source_template_id is null when it is created from Snapshot with its corresponding volume removed. Fix it by searching for volumes including removed. Also bring the logic of setting source template id to create() method than execute which was wrongly put in.
fix kvm issue, for windows sever 2008, it will crash without hyperv enlightment featre enabled
There are few cases that mgt server won't reponse agent's pingcommand timely, or in KVM's case, libvirt won't repsonse in few mintues, which will cause agent reconnect to mgt server, then all the on going tasks on host will fail
remove unused XS plugins
don't need to check if pv driver is updated, old pv driver should work
Snapshot support
Logic on SolidFire side for CloudStack snapshots
Support for back-end snapshots on primary storage
Logic around granting and revoking access to the volume that backs the snapshot
Changed "boolean connectVolumeToHost(VolumeInfo, Host, DataStore)" to "boolean grantAccess(DataObject, Host, DataStore)"

Changed "void disconnectVolumeFromHost(VolumeInfo, Host, DataStore)" to "void revokeAccess(DataObject, Host, DataStore)"
Invoke grantAccess and revokeAccess one time each using a SnapshotInfo (where previously a VolumeInfo was being passed in)

Handle the case where a SnapshotInfo is passed into the grantAccess and revokeAccess methods
Improve error handling for a host-side error
Pass on new command
Save off the UUID of the VDI before detaching its SR
Reply that reverting is not supported
Reorganized the snapshot logic a bit
CLOUDSTACK-7762 -[Automation] - Fix test failure for test_02_revert_vm_snapshots in smoke/test_vm_snapshots.py
fix expried certificate in unit test
CLOUDSTACK-7761:

Revert "when system VM ping times out, stop system VM"

This reverts commit ee23be1942001ab732cfb3ad50fa24163cb88a48.
Commits related to taking snapshots that live on primary storage