A full redesign of the Mesos CLI

The current Mesos CLI is in serious need of a upgrade. It was created a long time ago and hasn't kept pace with the rest of the code base. In fact, many of the current Mesos CLI commands do not work out of the box. For example, using any of the python CLI scripts such as “mesos-cat” will result in an error because the proper Mesos library is not in not in the $PYTHONPATH by default.

This Epic proposes a redesign of the Mesos CLI including (but not limited to) the following:

• A complete rewrite of the CLI, from the ground up, with a more pluggable architecture, better help information, and bash-autocompletion
• A full test suite for the CLI that is closely tied with the Mesos unit tests so CLI commands will be updated as Mesos features change
• A new set of container-related commands in the vein of "docker exec", "docker ps", "docker top", "docker logs", etc.
• Both a local and a remote component so you can debug locally using the CLI or gather information / launch cluster wide commands from the same CLI

Design doc:
https://docs.google.com/document/d/1r6Iv4Efu8v8IBrcUTjgYkvZ32WVscgYqrD07OyIglsA/edit?ts=57573bba#