Enable loading multiple dataset repositories #4
Description
It is often useful to compare different applications (with their own distinct repositories), or two versions of the same repository. For this reason, we should add the possibility to use multiple dataset source at the same time.
In the interface, we could replace the repository location textbox with a settings page (or popup) where it would be possible to add links to multiple repositories. Then, the JSON objects found in list.json of every data repository could be combined into a single (probably hierarchical) list that will be passed to whatever procedure we use to select the individual datasets (see #1).