DB48X: HP48-like RPL implementation for DM42

[M0R33z]

@c3d

I am currently testing equations with collect and expand.
Example: 60*x+x*192*x

-> Simplify returns: 60*x+192*x*x
-> Expand and Collect returns the same result: 60*x+x*192*x

I would have expected Collect returns: 60*x+192*x^2
On the HP48GX I get exactly this result