Gauges clamp to a minimum or maximum value when out-of-range

[gbakeman]

Based on nutdotnet/WinNUT-Client#136

When an out-of-range value is applied to a gauge, it appears that the gauge will then clamp it to the nearest minimum or maximum value of the gauge its self. The value on the gauge should be displayed as accurately as possible, while we need an alternative way to communicate to the user that the value is out-of-range. Perhaps allowing the gauge needle to travel slightly off the gauge's limits, while showing an icon with text alerting the user to what's wrong.