(issue1754) Also fixup master artifact for already loaded recommendations As the load many call creates (and needs to create) all artifacts in the reccomendations this would break "old" recommendations after a reload through the "Pencil" mode. A better fix would probably be to just set the master artifiact in the recommendations but due to the extremly weird interaction with the server at this point it is not trivial to identify how this can be done.

- Validation of the input values of an incoming feed() call