Added i18n support and the i18n lint tool to wrap the template strings in {% trans %} tags

This will allow you to internationalize your static site easily and create separate sites for each language under .build/en etc.

First you need to wrap your string in {% trans %} tags so you can create po files.  The[i18n lint tool](https://github.com/rory/django-template-i18n-lint)  will help automate this just run
```bash
cactus i18nlint -r
```

Next you need to create po files just run the following for each langauge.  See [Django docs for makemessages](https://docs.djangoproject.com/en/dev/ref/django-admin/#django-admin-makemessages)
```bas
django-admin.py makemessages -l en
```

Then send your po files to your translators when you get them back run
```bash
django-admin.py compilemessages
```

After that you can run cactus build or serve and it will create subdirectories for each language code.