Setting capacity on containers

[kevin-w-du]

It will be better if we can put a capacity limit on hosts (or routers), so the container's usages of the CPU, RAM, or other resources are limited. This is useful for demonstrating denial-of-service attacks. Not sure how to do this in docker, but it should be doable. This could be a set of APIs at the node level (one API for setting each type of resources).