#411 Support virtual/physical resources for MM standby support

[Steve Sherman]

MMs operate in an active and standby role. When the
active fails, the standby takes over automatically. To
model this, we'll use a virtual resource to represent the
"consistent" MM functions, while physical resources
represent the actual MM themselves. We'll base our
modeling as much as possible as described in the ATCA/HPI
specification. This allows applications to more easily
support both environments.