Added a new widget, MinMaxAvgWidget, a simple widget
that displays values in 'min, max, avg' fashion.
it has a setMaximum, setAverage and setMinimum
methods, that is userful for setting the minimum,
maximum and average of stuff. Ah, it also shows
the minimum, maximum and average of things.
Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
