In-place Update of Pod Resources

This proposal aims at allowing Pod resource requests & limits to be updated in-place, without a need to restart the Pod or its Containers. The core idea behind the proposal is to make PodSpec mutable with regards to Resources, denoting desired resources. Additionally, PodStatus is extended to provide information about actual resources applied to the Pod and its Containers. This document builds upon [proposal for live and in-place vertical scaling][] and [Vertical Resources Scaling in Kubernetes][]. [proposal for live and in-place vertical scaling]: https://github.com/kubernetes/community/pull/1719 [Vertical Resources Scaling in Kubernetes]: https://docs.google.com/document/d/18K-bl1EVsmJ04xeRq9o_vfY2GDgek6B6wmLjXw-kos4 This proposal also aims to improve the Container Runtime Interface (CRI) APIs for managing a Container's CPU and memory resource configurations on the runtime. It seeks to extend UpdateContainerResources CRI API such that it works for Windows, and other future runtimes besides Linux. It also seeks to extend ContainerStatus CRI API to allow Kubelet to discover the current resources configured on a Container.