remove double string replace (now less allocations); only add up values
if they're valid numbers.
builtin int.Parse throws with "1 2", but users can type stupid stuff
like that in the program (so we parse as 12).
be explicit that the string is empty rather than possibly missing
disallow encrypted export for BK4 (they're not encrypted), removes type
check
simplify replaceall in showdownset (don't call ReplaceAll 4x, just get
valid chars and rebuild)
simplify get ribbon sprite name (precompute ToLower and appended values
