Correct API versioning for the vdi.copy extension

Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Bump API version to 2.2

Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Merge pull request #1613 from robhoes/clearwater-felton

Clearwater felton
implement PCI database merging

Signed-off-by: John Else <john.else@citrix.com>
pci_db non-optional

Signed-off-by: John Else <john.else@citrix.com>
Add unit tests for Pci_db.merge