scope replaceKeywordPlusQuotedBlock_dyn

sinterface #IReplacer {
  S[] get(LS tok, int iOpening);
}

// finds "<keyword> <quoted> {"
// func: tok, iKeyword -> S[] {beg, end}
static LS replaceKeywordPlusQuotedBlock_dyn(LS tok, S keyword, IReplacer f) {
  for (int i = 0; i < 1000; i++) {
    int idx = jfind(tok, keyword + " <quoted> {");
    if (idx < 0)
      break;
    int j = findEndOfBracketPart(tok, idx+4);
    
    S[] be = f.get(tok, idx);
    tok.set(idx, be[0]);
    clearTokens(tok, idx+1, idx+5);
    tok.set(j-1, be[1]);
    reTok(tok, idx, j);
  }
  ret tok;
}

Began life as a copy of #1009010