Prior to this commit, when the guest capability attempted to expand a path with spaces it would quote the path passed in. However if the path also had a relative path those quotes would end up making `printf` ignore it and not properly expand the path fully. This commit updates that to first escape the quotes of a path and then pass in the new path to be expanded.
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.