When a compute service is allocating ports with the network service,
it needs to pass across information about the capabilities of the
compute host. Currently each plugin provides information about its
own capabilities. This introduces a ComputeInfo class which,
initially, just contains a dict of PluginInfo classes.
With this change, there is a versioning constraint between the
compute and network hosts. The compute host must not pass the network
host a ComputeInfo object with a version that the network host
is unable to deserialize(). This implies that as a general rule the
version of os-vif on the network host must be at least as new as the
version on the compute hosts. During a live upgrade, the network
hosts must be upgraded before the compute hosts.
Change-Id: I7b51c97b5e03ffa51a56ceb3d4f97e188508379d
9686110d53