Fix title attribute typo
Remove image links

1. Links to Picasa will get an icon, but these can not be disabled in
css for <a><img>, without relying on jQuery.
2. Links on images were only added because text links to Picasa never
stood out.
3. With the icon, text links to Picasa do stand out, so there is not
much harm done removing them from images.
4. This makes for a simpler syntax in Markdown and easier maintenance
(since each link only appears once).
Style image caption