Why loop instead of forloop?

Since h2o is based on Django templates, why did you choose to rename some of the loop variables?

Django:

```
{% for item in list %}
    {{ forloop.counter0 }}
    {{ forloop.parentloop.counter0 }}
{% endfor %}
```

h2o:

```
{% for item in list %}
    {{ loop.counter0 }}
    {{ loop.parent.counter0 }}
{% endfor %}
```

This makes templates non-portable (or less portable)
