opVisitVerbs

The op "visit" verbs
  There are three verbs in Drummer that are different from the others. This is where we explain how they work.
  The three verbs are: op.visitAll, op.visitSubs, op.visitToSummit.
  They make it easy to write script code that applies to all headlines in the outline, all the subs of the bar cursor headline and all the headlines on the path from the bar cursor to the summit of the outline.
  Inside the callbacks, you can get the text of a headline, or attributes.
  You can stop the traversal by returning false from the callback, or return true to continue.
op.visitAll
  var ct = 0;
  op.visitAll (function (headline) {
    ct++;
    console.log (string.padWithZeros (ct, 4) + ": " + headline.getLineText ());
    return (true);
    });
op.visitToSummit
  op.visitToSummit (function (headline) {
    console.log (headline.getLineText ());
    return (true);
    });
op.visitSubs
  op.visitSubs (function (headline, level) {
    console.log (string.filledString ("\t", level) + headline.getLineText ());
    return (true);
    });