No undefined literal in SimplLang, because it doesn't exist in JS.
Class "Expresses" moved to AE.hs, because it only involves sub arithmetic expressions.
All AE-analysis-specific classes out of SimplLang.hs into AE.hs
HasVariables IS INDEED used in Types.hs, reverting, sorry.
ST.hs and Hjs2Simpl included in the build (cabal file). Fixed most obvious errors.