Manual whitespace control doesn't seem to work

The Jinja specification allows for manual whitespace control by adding a minus at the start or end of tags (http://jinja.pocoo.org/docs/dev/templates/#whitespace-control) like:

```
{% for foo in [1,2,3,4,5,6,7,8,9] -%}
{{ foo }}
{%- endfor %}
```

This code should yield `123456789`. However it yields

```
1

2

3

4

5

6

7

8

9
```