New community view

If there are no marketplaces (i.e. new installation) show a simple form for marketplace creation. Creates also admin user.

Todo
- [x] New view/controller to create the first marketplace
- [x] Before filter to ensure that there are no marketplaces yet
- [x] Take a look at the CSS, does it need cleaning?
- [x] Add high plan level
- [x] Skip admin user confirmation

![screen shot 2014-12-18 at 14 01 50](https://cloud.githubusercontent.com/assets/429876/5487790/7792cb7c-86be-11e4-9ff1-0bb9c552f451.png)