Code review comment for lp:~andrea.corbellini/beeseek/homepage

This branch modifies the initial search page adding three short portlets: one that explain what is BeeSeek, the second how to try it and the last invites people to join the project.

A way to see the changes is to run BeeSeek with `./beeseek-server start --testing` and then look at http://localhost:8080 with the browser. Doing that you should see the new content. The old page layout can be seen on http://beta.beeseek.org.