some widgets, almost finished. range sliders and a gradient editor.
all tested only in horizontal orientation. sliders have a bug where the range between two sliders is painted incorrectly.
RangeSlider is just that
FloatingRangeSlider adapts to the handles. When they go outwards, the range adapts. When they go inwards... the range adapts.
FloatingGradientRangeSlider is just like the previous slider, but shows a gradient.
licensing: public domain, no attribution, nothing (leave me alone).