View Layer token

Well, title says it all... but I'll to explain it better:

I do work a lot with different "ViewLayers / RenderLayers" and sometimes I need to re-render again single or multiple separates layers and I have to go changing the name of the output image file again, and again... time consuming and prone to typing or naming errors.

So I propose to add a mini "token" system on the output render tab like "#LayerName" so every time I re-render a single ViewLayer it changes the output automatically.

A couple visual examples as image to ilustrate it better.

Example A: Used token for file name. Example B: Used token twice, folder name and file name.

I hope it makes sense...

Cheers, Ignasi aka Topeich