Behavior preferences used a nested QTreeWidget with groups like General,
Audio, Timeline, etc. Replace it with one tab per group in the left sidebar
so users can jump directly to a category without expanding a secondary menu.
Also wire double-clicking a node in the node graph to emit a selection
signal with its context, causing the parameter panel to scroll to that
node's parameters (in addition to showing/raising the panel as before).
Mike-Solar
f57ffa482f