references #21 of the original repository. a directive looks wrong

This PR references #21

The coffee code looked wrong. it generates an empty link function and doesn't respect the syntax of the directive.

Compare the original generated code:

```
directive("scrollableContent", function() {
    ({
      replace: false,
      restrict: "C",
      link: function(scope, element, attr) {}
    });
    adjustScrollableHeight(element.parent()[0]);
    return setTimeout((function() {
      var iscroll;
      [].slice.call(document.querySelectorAll("input, select, button, textarea")).forEach(function(el) {
        return el.addEventListener(("ontouchstart" in window ? "touchstart" : "mousedown"), function(e) {
          return e.stopPropagation();
        });
      });
      return iscroll = new IScroll(element[0], {
        checkDOMChanges: true
      });
    }), 200);
  });
```

and the new generated code:

```
directive("scrollableContent", function() {
    return {
      replace: false,
      restrict: "C",
      link: function(scope, element, attr) {
        adjustScrollableHeight(element.parent()[0]);
        return setTimeout((function() {
          var iscroll;
          [].slice.call(document.querySelectorAll("input, select, button, textarea")).forEach(function(el) {
            return el.addEventListener(("ontouchstart" in window ? "touchstart" : "mousedown"), function(e) {
              return e.stopPropagation();
            });
          });
          return iscroll = new IScroll(element[0], {
            checkDOMChanges: true
          });
        }), 200);
      }
    };
  });
```
In the original generated code, `element`of  `adjustScrollableHeight(element.parent()[0]);` is undefined. the rest of the code does not follow the definition of a directive.

this PR is fixing the error and generates a correct directive, at least from my point of view.
However, I can't get firefox to scroll properly.
It does work with overthrow, though.