add john hunter announcement onto the website

this is almost the same version as what can be found on matplotlib
website
add link in sidebar
Merge pull request #11 from Carreau/john_hunter_memorial

Add announcement about John Hunter's death to main site and link to the memorial fund page.
Small text fixes.
update for 0.13.1 release
Add donation button.
Add standalone donation page.
Small tweak to donate button
Move donate tile further down the sidebar.
Move Wiki link from navbar to sidebar
Remove duplicate Videos link (now in navbar)
Update FAQ, removing obsolete entries
Merge pull request #13 from takluyver/nav1

Tweaks to navbar & sidebar
use relative path to ipython.css in agogo theme
add donate page to toc

Fixes sphinx warning when building site
add fancybox js and css to _static files
add IPython screenshots page and images

closes gh-12
Merge pull request #14 from jtriley/add-screenshots-page

Add screenshots page.
Announce Sloan foundation grant
Improve Sloan grant announcement.