No absolute paths

Issue #187 resolved
Benjamin Cordes created an issue

I'm not entirely sure, but I think it would be better to have all resources loaded as resourcestream, without absolute paths. A few things depend on absolute path. OptionsJson uses

JSONObject fileJSON = (JSONObject) (parser.parse(FileSystem.readFromFile(filePaths.get(i))));

There are some solutions which uses Apache's commons io, which I think are easiest. ResourceStream seems to me to have some strange edge cases, when used inside an IDE.