Cleanup templates

Unused tags
Unused templates
Leftovers pinax-pages templates

Cleanup pages for readability

This removes images, and giant headers, and makes the text - not white.
The next layer down in CSS is blue, so that's it for now.

This helps understand what's on the page visually, so this, at the
least, make testing easier for now.

Remove wagtail

This should eradicate wagtail from the project.

While wagtail may be nice, our goals are to keep all things public, and
having things locked behidn a DB is congruent to that plan.

All in all, the django project only leveraged a single wagtail feature,
"richtext" which has been hacikly removed and will result in bad display
of however it comes up. But this is on homepage.html, which will be
removed and covered up with a static website, which means we should be
able remove homepage entirely from this project.

This reduction hopefully makes the monolith easier to understand,
maintain, and wield.

Default content page and sponsor list is working, mostly.
TODO: get sponsor logos to show up instead of the names (text).

Getting the splash homepage to work via CMS.

Nearly there. Much rubbish / cruft ripped out of site_base.html and content_page.html.
Had to modify cms_pages/models.py to accommodate a "simple" layout option in the homepage
editor.
Still some stuff to do. Styling not quite there yet, but want to checkpoint this.

September website changes - Pre-registration (#66)

* Factors rendering of external links into its own template. Automagical!

* Adds wagtail templates for keynotes on the front page

* Migrates to Wagtail 1.6

* Migrates content pages to be a streamfield. Flexibility++.

* Fixes editing of ContentPage bodies

* Adds floating images to content pages

* Fixes the layout of floating images

* Adds anchor links to content pages.

* Adds presentation link to the keynote speaker block model

* LCA-ifies the schedule list

* Refactors cms_pages/content_page into a new base template

* cms_pages/content_page now derives from abstract_content_page

* news_index_page now derives from abstract_content_page

* news_page now derives from abstract_content_page.html

* utility_page now uses the content_page base template

* Factors out _right_floating_image.html

* Themes the presentation detail page

* Themes the speaker profile page.

* Themes the schedule list page.

* Minor work on schedule_conference.html

* Themes schedule_detail.html

* Replaces cradle.svg

* Adds a background image to the schedule pages

* Adds libravatar fallback for speaker profile images

* Adds new background images (must update colophon)

* Adds some magic so that we can have slightly different presentation backgrounds for different pages.

* Adds the sponsor block to the bottom of the page.

* Adds sponsor logos to footer.

* All migrations are now in this tree

* Fixes wagtail migrations

* Adjusts presentation_detail to allow for miniconfs (i.e. no target audience)

* Adds unpublishing to presentation detail

* Adds ScheduleHeaderParagraph, which allows us to add some text to the header of schedule pages.

* Adds NamedHeaderParagraph. It allows us to store header paragraphs in the CMS.

* Date formatting in the schedule

* First step for fixing images

* Allows us to automagically load the colophon

* Adds “publish changes” button.

* Can login with email address