rgblink scramble could be even more scrambled to expose more mistakes

while the scramble flag does serve its purpose of showing when you forget to bankswitch, it introduces two new issues:

1. it hides alignment mistakes, as sections generally get placed at `$4000`
1. it hides mistakes where data is read out of bounds, since all data past a section is usually $ff

possible solutions for each issue:

1. try to put sections at the end of a bank, or avoid putting sections at `$4000` (the former is probably better)
1. allow for randomising section banks instead of putting each section in its own bank

the second one probably isnt as much of an issue as the first, as its _me_ not testing the non-scrambled build..