PowerVM hypervisor plugin

Convert PowerVM hypervisor configuration in Nova to the new plugin setup.

Change-Id: I3ec700c5eab3fb2e63a4b2717ddbaf9702974c73
OpenVZ hypervisor plugin

Convert OpenVZ hypervisor configuration in Nova to the new plugin setup.

Change-Id: Id3e39ab3be74bb8757a73645359e1061ce7e76cd
Merge branch 'config-local' into dt-test
Merge branch 'fix-get-packages' into dt-test
Merge branch 'hypervisor-openvz' into dt-test
Merge branch 'hypervisor-powervm' into dt-test
Merge branch 'ldap-ad' into dt-test