Ensures that a VM won't:
(a) Have provisioned more RAM than there is available on a given node.
Due to memory overprovisioning, this is simply a "is the VM memory count
more than the node count", and doesn't factor in free or used memory on
a node, total cluster usage, etc. So if a node has 64GB total RAM, the
VM limit is 64GB. It is up to an administrator to ensure sanity *below*
that value.
(b) Have provisioned more vCPUs than there are CPU cores on the node,
minus 2 to account for hypervisor/storage processes. Will ensure there
is no severe CPU contention caused by a single VM having more vCPUs than
there are actual execution threads available.
Closes#139