`rake generate_session_store`
A lot of people think `rake config/initializers/session_store.rb` needs to
have an existing session_store.rb file in order to generate it. This task
will make it easier to explain and document.
git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@3267 e93f8b46-1217-0410-a6f0-8f06a7374b81