Some PEP8ification
More text on the accept invitation page.
Add a message to a newly invited user after setting their password.
Add link to share instance on home and add speech pages.

Plus new speech/section buttons on the home page.

The templates in the sayit app don't have very many blocks at the
moment, which makes them rather hard to extend. django-apptemplates
allows us to extend the templates from speeches without having to give
them new names.