N-Queens on 50g (RPL language)

[xerxes]

Thanks to Claudio for the effort and comparisons.

And special thanks to Werner for this impressive solution and the new test code for userRPL.

Besides the 49G and 50G, I've updated the results of the 28C und 28S (normal and turbo speed).

Unfortunately I had to remove the userRPL results of the 48SX and 48GX and also the sysRPL result
of the 48GX, because these are not comparable any more.