Function copyObj

static/editor.md/lib/codemirror/lib/codemirror.js:8098–8104

(obj, target, overwrite)

  };

  function copyObj(obj, target, overwrite) {
    if (!target) target = {};
    for (var prop in obj)
      if (obj.hasOwnProperty(prop) && (overwrite !== false || !target.hasOwnProperty(prop)))
        target[prop] = obj[prop];
    return target;
  }

  function bind(f) {
    var args = Array.prototype.slice.call(arguments, 1);