Put the calculator form inside the CARA template.

It is easier to review this as 2 commits:

a235fb2f: Moves the files around

2b8f44b7: Twiddles with the layout so that it works well for both the index page and the form

From a technical perspective, good to get @gaazzopa's view on this. From a design perspective, @andrejh would you mind looking at the form again to confirm you are happy for the template to be used. The form can be found at http://test-cara.web.cern.ch/calculator/ (still building, but should be there in < 3 mins).