function inflate(rect, w, h) {
		return create(rect.x - w, rect.y - h, rect.w + w * 2, rect.h + h * 2);
	}
Inflates the rect in all directions.

@method inflate
@param {Rect} rect Rect to expand.
@param {Number} w Relative width to expand by.
@param {Number} h Relative height to expand by.
@return {Rect} New expanded rect.