Shapespark releases

@haruhime The number input for rotation speed has some problems accepting negative numbers, which we will fix, but you should already be able to enter negative numbers with some effort (try for example pressing & dragging the mouse button on the number input or enter a positive number first and then add a ‘-’ in front as the last step)

@shyan supporting rotation around any axis/angle is larger effort and we don’t have plans to do it soon. The scene storage format doesn’t have information where is the center of an object. Rotating around the UP axis (yaw rotation) was easiest to support, because it works well with an approximate rotation point at the center of an object bounding box, but other axes do not work well with such approximation.