Silly error fixed and more graphical improvements

Fixed another recent error caused by trying to save every byte of memory. When Mario jumped onto a lift and landed while the lift was at the same height as the girder he jumped from, Mario died.

In the final fall, the monkey has its mouth open, making the animation more similar to the arcade version.

A little colour improvement when entering a name in the high score table, which probably no one will notice.

On Dubna, the monkey doesn't flicker when jumping to the left in the opening animation.

I think that might be enough for this game. There are still a few things to improve that I unfortunately didn't get to, but it is probably time to end this project. I know I didn't implement some of the players suggestions that are still on my list of possible tweaks. Sorry! Lately, it has just been about the fiftieth way of freeing up some memory and making a small change or fix. I am glad that I finally managed to get the entire arcade version, including music and all animations, to work properly on Spectrum 48K and all compatible computers (except maybe Spectrum Next and those for which I couldn't find any emulator or users), plus some small additions for Spectrum 128K and Didaktik Gama.

But I don't rule out returning to this game at some point, although I have no specific plans, and probably only if someone finds some errors or emulators for other Spectrum-compatible computers, or if I suddenly think of a new way to free up some memory or some new interesting simple improvements.

The last thing I would like to do at the moment is to modify this version for SAM Coupé with proper sound. I haven't done that yet because I didn't want to do every previous modification for two versions.