There are still issues, especially with "gnt-instance modify" and
resetting values. However, this is a start.

Reviewed-by: ultrotter

Reviewed-by: ultrotter

Vim doesn't recognize the format automatically.

Reviewed-by: ultrotter

We no longer use YAML in Ganeti at all. This patch converts the QA
configuration from YAML to JSON. JSON doesn't support comments and
I had to use a hack with fields starting with '#'.

Reviewed-by: ultrotter