New homepage with search box

Related to https://github.com/hoaproject/W3/pull/18.

Here is the current state: ![home](https://cloud.githubusercontent.com/assets/946104/4391011/90fd47cc-4401-11e4-8307-57b9bcaee0cd.png)

What happen when we click? Not yet defined. Maybe we should remove the list of libraries and output the results from search.hoa-project.net?