Will/fix i18n in ai branch

My last merge to the AI grading branch broke the i18n scripts because `BASE_DIR` was moved from `settings/base.py` to `settings/test.py`.  This fixes the issue by moving `BASE_DIR` back.

I've also generated translation strings for AI grading, which we'd need to do eventually anyway.

@stephensanchez 
Ah ok.


On Mon, Jun 9, 2014 at 11:21 AM, Will Daly <notifications@github.com> wrote:

> In settings/base.py:
>
> > @@ -151,6 +151,8 @@
> >
> >  }
> >
> > +BASE_DIR = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
>
> To go up one directory from settings to the repo root.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/edx/edx-ora2/pull/417/files#r13545888>.
>