Allow a way to revert back to an old function/view etc.

[MaxShadow]

When ever Mozilla makes changes to how something works or looks we usually HATE it.

When you make these changes, allow us to decide for our selves if we want accept the NEW look or function or allow us to revert back to what we had with a simple on off switch.

We usually have to rely on an "add on" to undue what you needlessly change.