User-defined functions in Free42

[Thomas Okken]

Deciding the number of inputs and outputs dynamically could be handled by having another function that overrides the number saved by FUNC. That would be pretty easy to implement, since the two-digit number passed to FUNC is just saved to a hidden variable and not used until RTN and friends perform the stack restoration. Maybe in some later release... I just released 2.5.24 with FUNC nn and RTNYES/RTNNO/RTNERR, let's see how that goes first...