narval #2557341 Remove the custom interpreter [validation pending]

Remove the custom graphical language interpreter and use a bare Python script as recipe.

prioritynormal
typetask
done in4.0.0
load2.000
load left0.000
closed by#c95cee9bfe06 narval v4: recipe is now a python script; no more actions
patchadd migration script for narval 4 [applied]narval v4: recipe is now a python script; no more actions [applied]