For ages I've had problems with 256-color xterm and vim. I never
used a proper colorscheme, but just modified the default I was
"magically" given. This changes all of that to make us now have
a proper color scheme -- the "adam" scheme.
Colors now work independent of console color depth, I think.
There are remaining quirks, but I'll have to add the requirements
as proper color mappings to my color scheme file.
