As Parallels Cloud Server product was renamed within Parallels company rebranding
we need to change its reference in feature support matrix and documents accordingly.
A parameter 'virt_type' in libvirt section of nova.conf will remain 'parallels'.
Since libvirt version that supports 'vz' starts to report it as a hypervisor type,
we add a new hv_type 'vz' in the list of known hypervisors.
DocImpact.
Change-Id: I536e4284927508a813edd05f185f7ba0ed76d38c
implements: blueprint rename-pcs-to-virtuozzo
bc3b6cca47