Enable more than one jade template file to be used in hapi.

At the moment only one jade template can be configured because the filename property is set in the compileOptions for the view engine, in the case of Jade this should be done at compile time.

I have updated the Jade views example to include a separate layout and two templates illustrating how this change can be useful.

I have simply included the filename parameter in the instance of compileOptions created prior to the call to view engine.

Note: At this stage I have not labeled it as a Jade specific change, I can if you like.