Removes old sidebar base and original symposion styling.
Imports new style and css and images, and updates site_base.html into a static page that displays the splash.

Next up is teasing out the splash-page parts and other content parts so our other templates work.
Removes facebook icon from the page. We don't have one.
Montréal has an accent.
Add block extra_head.
Moves homepage content to the homepage.
whitespace
Fixing links
Extract block excerpt for site_base usage.
Reformat about for new style.
Adds extra address styling (left margin).
Removes unused template tag.
Updates venue for the new skin.
"Merge" to use taavi-new-layout branch in favour of the work already done on pyconca2013.