Y-axis - checkbox to disable auto-scaling

[laminat0r]

Sometimes it's nice to have the y-axis begin at zero, rather than a scaled parameter based on the values in the timerange.

Especially for disk capacity etc, in context of multiple disk usage values you often want an overall usage-at-a-glance rather than highly detailed information on fluctuations in the past hour.

A checkbox toggle of some kind would be awesome