Actually use options.tags

Fixes #1.

As a mostly unrelated side note, clearing the default list makes JSX interestingly useful outside React. Just a thought.

```jsx
// jsx
var operationList = (
    <OperationList>
        <Operation cmd="cmd1" arg="a c d" />
        <Operation cmd="cmd2" arg="b c" />
        <Operation cmd="cmd3" arg="a b" />
    </OperationList>
);
```

```js
// js
var operationList = OperationList(null, [
    Operation({cmd: "cmd1", arg: "a c d"}),
    Operation({cmd: "cmd2", arg: "b c"}),
    Operation({cmd: "cmd3", arg: "a b"}),
]);
```