Refactor, fix bug regarding settings reset, and add a way to retrieve ports in JSON format.

I Refactored the code so that the file structure is easier for further evolutions.
- Moved most of the directory in /app.
- Moved routes in /app and not in /utils.
Prepended routes that returned json by /api.
Fixed a bug that reset the user settings when clicking on "Save".
- The settings will now not be created if not put in the request but it avoids them being overriden by empty string as it was before.
Added a new route that allows to retrieve the ports in a json format (can be useful later to create some agent that would need to compare ports between Portall and the monitored machine)

need4swede / Portall