Remove ignore=dirty from .gitmodules.

Removing ignore=dirty from .gitmodules to replace it with what we really
want: Add *.pyc to global git ignore list.
Merge pull request #739 from glogiotatidis/update-gitmodules

Remove ignore=dirty from .gitmodules.
Add django-database-email-backend dependency.
[bug 1007077] Add example to enable email debugging in local settings.