* node-mixin: Improve nodes dashboard
- Use stacking where it makes sense.
- Normalize idle CPU so that stacking is more meaningful.
- Consistently fill where stacking is used but don't fill where not.
- Fix y axis max value for Idle CPU panel.
- Fix y axis min value for memory usage panel.
- Use `$__interval` for range where applicable (and set min step
to 1m).
- Make the right Y axis for disk I/O actually work.
This is just an incremental improvements. It doesn't touch the more
involved TODOs.
Signed-off-by: beorn7 <beorn@grafana.com>
7ef6f2576d