Everything is in the title...
Brink back the search feature
The search layout has been removed in 755f2e3 by mistake. We can't
simply bring back it since the Google web search API is deprecated.
Therefore, the search feature now uses a Google custom search engine.
@willdurand : I took the liberty to attach the engine to my Google account but if you want to have control on it, feel free to create another one and update the key.
I'm fine with that.