Add In1.Cu and In2.Cu

[jdiez17]

[set-soft]

Try "Inner.N", as an example I use:

 - layer: Inner.1
   suffix: GND_Cu
 - layer: Inner.2
   suffix: Power_Cu

Looking at the code N can be any number:

   if s in D:
       layer = PC.LayerInfo(D[s], False)
   elif s.startswith("Inner"):
       m = re.match(r"^Inner\.([0-9]+)$", s)