Scaling was previously incorrectly rendering the source with another effect forced onto it, resulting in slower rendering and some sources that would no longer render properly.
Additionally the new option allows the user to have the source render at the original resolution in order to allow previously applied transform to stay identical. The rescaling however will no longer apply to filters after this source then, thus the speed bonus is lost.
Also categorized the localization file and adds descriptions for existing and new properties for Source Mirror.
The source allows you to apply effects to the same source without requiring a new instance of the source. Any changes done to the original source also apply to the mirror, so there is less total work that needs to be done.
It can also rescale the source, allowing you to use the same source as a cheap instant backdrop with Blur for example. What you do in the end is completely unwritten and up to you to decide.
Michael Fabian 'Xaymar' Dirks