How to Enable Horizontal Scrolling in Ubuntu 14.04

How to enable edge/horizontal scrolling on Ubuntu 14.10/14.04. How to fix the mouse-touchpad horizontal scrolling not working in Ubuntu 14.10/14.04. By default, in Ubuntu 14.04 (Ubuntu 13.10 also), the mouse-touchpad is set to scroll vertically instead of horizontal scrolling. Luckily, there is a way to tweak this setting and enable horizontal scrolling on your laptop. […]