Änderungen

Make Hot.Instruction.Compiler.typeOfExpr monadic
This change is important to keep the bytecode correctly typed when 
converting integer literals to reals in real context. Let's consider
this example: `R2S(-(180))`. This would force the argument to R2S into
real context but `typeOfExpr` would correclty return `integer` for 180.
So the emitted neg instruction would convert from integer to the wanted
real type. The fix to this is to check the wanted type in typeOfExpr
when an integer literal is passed.
 (commit: 84ca173)

RT: Print target register in lit instruction
 (commit: 9aa6913)