We store our network config in /etc/network/interfaces instead.

We now use that split-button everywhere to make the GUI more consistent.

That way we can specify a filename (required for android client).

VMID 0 will be used by spiceterm for task that run on the host.

- remove command from index (so that pvesh does not list it)
- use POST instead of GET
- correctly check permissions
- return value with status codes and data (allow expections)