Database configuration webapp/gui

[MJochim]

@georgraess and @raphywink have developed a method to change database configuration (DBconfig.json) from within the EMU-webApp. This feature is not yet publicly available. It would be the first GUI approach to designing DBconfig.json.

Which app is the right place?

We (@raphywink and I) now both think that the EMU-webApp is not quite the place for this. It is too cluttered and should be restricted to its main purpose, which is visualization and annotation of data. The emuDB Manager would be a better place for this feature, in terms of separation of concerns. However then, people using emuR but not the Manager could not benefit from the feature.

For the long term, we agreed to offer this feature in emuDB Manager, but also on a separate github-pages site. This way, all Emu users can take advantage of it. We should therefore implement it as modularly as possible (which we should anyway, but now we have a definite reason why ;) ).

Which API is the right place?

Currently, there is no way for a client to tell any server (neither emuR's serve() nor the node.js server) to update DBconfig.json. Only the backend API of emuDB Manager (which is reachable via HTTPS POST) accepts a command to change two specific options of the configuration.

The EMU-webApp implementation involves a change to the EMU WebSocket protocol. It remains unclear (to me) whether the WebSocket protocol is the right place for this or whether it, too, should be restricted to data visualization and annotation. But effectively it will need to be here, so emuR's serve() can be used without the Manager involved.