Wagtail integration (#17)

* Adds basic wagtail app to the website

* Renames lca_website to cms_pages for clarity; re-instates pinax-boxes until we remove them from the templates

* OOPS

* Just Enough Wagtail

* Removes the template view homepage from urls.py

* OOPS

* Makes the home page use a stream field

* Removes an irrelevant migration that I accidentally introduced.