Prior to this commit, if you tried to save a snapshot without giving it a name, the hyper-v driver would not properly obtain a vm id to save a snapshot on, resulting in an error. This commit updates the command snapshot save to hold onto the machines ID in argv rather than `pop` it off, so that the hyperv driver can obtain the guests id when saving a snapshot.
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.