- A booting VM is named by its address's reverse DNS entry. Without one,
the address itself was taken as the name, so its first number ("10",
"192") named the VM: a user who made a VM with that name had their keys
given to every such VM. Such an address now gets no keys; its metadata
hostname is still the address.
- Keys are written as quoted YAML strings, so a comment with an apostrophe
or ": " no longer breaks the key or the file.