New earth image plus minor fixes to main pages
undo changes in application.html.erb (these changes made in tutorials branch, to be merged later)
remove tutorials data from en.yml
undo changes in application.html.erb (these changes made in tutorials branch, to be merged later)
remove tutorials data from en.yml
Update main.css.scss with "click" class.
Merge pull request #53 from goobertron/minor_updates

Minor updates
Merge branch 'master' of git://github.com/diaspora/diaspora-project-site