Base conversion (and alphabetizing imports)

Racpete can now translate numbers between bases! I also made things alphabetical because it was bothering me. The convert-base code is pretty ugly, I think, but I couldn't figure out a good idiomatic way to do it. Point me in the right direction and I can fix it :)
Use a let here to avoid doing the string-split multiple times. Also Consider using cadr caddr and cadddr instead of second third etc. Although this is just personal preference and yours is probably more readable :)