Added selection of real visualizations (not only strings), that the user has installed, when creating a new space. Foundation for the marketplace for visualizations. New users have the default visualization 'List' already installed.
Differentiating between models and searchable models.
ModelConversion: modelToMap does not need class to be passed explicitly, can be inferred from passed object.
Moved Connection to utils, as it is not really a controller in the Play-MVC sense.
Added market for visualizations. To be developed.
Added installing/uninstalling a visualization to the market.
Finally loading spaces properly: POSTing JSON and loading the returned URL in an iframe.