Currently this can only be made to work in firefox and not in nautlis, yelp, ... with the following workaround:
1. Open a terminal and enter the following command:
$ sudo nano /etc/X11/xorg.conf
2. Change the "Configured Mouse" protocol to:
Option "Protocol" "Auto"
3. Add the following following line (this maps horizontal scrolling to your back and forward mouse button, horizontal scrolling by default has back and forward actions in firefox):
Option "ButtonMapping" "1 2 3 6 7"
Currently this can only be made to work in firefox and not in nautlis, yelp, ... with the following workaround:
1. Open a terminal and enter the following command:
$ sudo nano /etc/X11/xorg.conf
2. Change the "Configured Mouse" protocol to:
Option "Protocol" "Auto"
3. Add the following following line (this maps horizontal scrolling to your back and forward mouse button, horizontal scrolling by default has back and forward actions in firefox):
Option "ButtonMapping" "1 2 3 6 7"
It should look like this:
Section "InputDevice"
Identifier "Configured Mouse"
Driver "mouse"
Option "CorePointer"
Option "Device" "/dev/input/mice"
Option "Protocol" "Auto"
Option "ZAxisMapping" "4 5"
Option "ButtonMapping" "1 2 3 6 7"
Option "Emulate3Buttons" "true"
EndSection
4. Restart X (Ctrl-Alt- Backspace) .