app: add GimpMeter widget
GimpMeter visualizes a set of values that change over time. It consists of a gauge, showing the most-recent sampled values, a history graph, showing a plot of the values over time, and an LED, which can be used as a boolean indicator for some condition. GimpMeter is used in the dashboard dockable, added in the next commit.
Showing with 1226 additions and 0 deletions