[fix bug 976099] Redirect to current page after logging in.

You're correct. It's still a bit complicated though. Here's what you can do

```
                {% if not user.is_authenticated() %}
                  {% if request.get_full_path() != '/' %}
                     {% set next=request.get_full_path() %}
                  {% endif %}
                  <span id="login-menu-locator">
                    {{ browserid_login(text='Sign in', next=request.GET.next|default(next|default(''))) }}
                  </span>
                  or
                  <a href="#" data-reveal-id="join-modal">Join</a>
                {% else %}
```

and you don't need the `LOGIN_URL = "/"` in `base.py` anymore.

So what we do is that we check if there is `request.GET.next` and we default to `next` variable if there is not and similarly if there is no `next` variable we default to `''`