Split up API parts

[izzy]

To avoid invalid JSON files, single parts of the API file should be generated separately and put together by a more sophisticated JSON engine than the current echo/cat solution.

[izzy]

This is mostly fixed with the Python rewrite. A large part of the generation still happens on the gateway, though, where ideally the only thing that would be written to the webserver file would be the non-static parts like user count and the space open status while the static part would be a python dictionary residing in the config.py.