Bug 1030972 - Import tasks from Bugzilla

@bobsilverberg @Osmose r?
I don't want to call super because the method I'm overriding (from `django.views.generic.base.TemplateView` in Django 1.4) does something very silly. Here it is:
```
    def get_context_data(self, **kwargs):
        return {
            'params': kwargs
        }
```
Nothing related to `ImportTasksView` uses `params`, and I really just want to use `kwargs` to add keys directly to `ctx`. In any case, this behaviour is fixed in Django 1.5, where `TemplateView` inherits from `ContextMixin` [1]. When the project moves to a different version of Django, this method will have to be updated.

[1] https://docs.djangoproject.com/en/1.5/ref/class-based-views/mixins-simple/#django.views.generic.base.ContextMixin.get_context_data