Bulge Effect: Have middle-mouse-drag NOT move the bulge centre, but pan as per usual
When using the Bulge Effect, if you Middle-mouse "pan", the Bulge Center moves instead of panning around the image, which seems odd. I think this should not be the default behaviour - left-dragging the bulge centre should move it, and middle-mouse dragging should pan around the image, as it normally does.
Steps to Reproduce:
1. Apply the Bulge effect to a layer
2. While the Bulge Effect is selected, middle-mouse drag in the comp viewer window to pan it
Bulge Center moves.
View pans around. Bulge Center should only move when left-mouse-dragging.
Deselect the Bulge effect before panning