This PR is dependent on the 2.1.0 release of the vagrant_cloud library. It updates the `cloud` command to use the new interface for interacting with the Vagrant Cloud API. It also adds support for direct to backend storage uploads, and defaults to this method. Also included is a bit of cleanup refactoring, addition of method documentation, and fixing up some small issues around custom username usage within the internal client for authentication.
Vagrant Core Plugins
These are plugins that ship with Vagrant. Vagrant core uses its own plugin system to power a lot of the core pieces that ship with Vagrant. Each plugin will have its own README which explains its specific role.