Provide more descriptive usage error messaging

[nathanpotter]

When running a command with incorrect args, I would imagine the output would show more information. Right now it shows like the following:

I would imagine we would have something like:

$ kubectl get
You must specify the type of resource to get. Use "kubectl api-resources" for a complete list of supported resources.
error: Required resource not specified.
Use "kubectl explain <resource>" for a detailed description of that resource (e.g. kubectl explain pods).
See 'kubectl get -h' for help and examples

where it provides a decent message with info about running the command w/ the -h flag for additional details.