Since the root file system is marked as read-only, attempting to
link the shared directory to `/vagrant` will fail. If the guest
path is on the root file system and APFS is used, create the
link as a firmlink instead.
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.
Chris Roberts
Brian Cain
Chris Roberts
Seth Vargo